AGRIC.  PERT. 


REPORT 


Board  of  Directors  of  Drainage  District  No,  1 


PROGRESS  OF  WORK  TO  JANUARY  1,  1881. 


« 


AGRIC,  DEPT. 


if 

jf.«. 


REPORT. 


OFFICE  OF  DRAINAGE  DISTRICT  No.  1,  \ 

SACRAMENTO,  December  20th,  1880.  j 

1o  his  Excellency  GEO.  C.  PERKINS,  Governor  of  the  State  of  California: 

In  compliance  with  the  provisions  of  section  four  of  an  Act  of  the 
Legislature  of  the  State  of  California,  entitled  "An  Act  to  promote 
drainage,"  approved  April  twenty-third,  eighteen  hundred  and 
eighty,  the  Board  of  Directors  of  Drainage  District  No.  1  respectfully 
submit  to  your  Excellency  a  report  of  their  proceedings  by  virtue 
of  the  powers  conferred  upon  them,  including  the  amount  of  work 
performed  and  the  amount  of  money  expended. 

Drainage  District  No.  1  embraces  practically  all  of  that  portion  of 
the  State'  of  California  drained  by  the  Sacramento  Kiver  and  its 
tributaries. 

The  seventh  section  of  the  Act  to  promote  drainage,  provides  that 
"  after  the  formation  of  any  territory  into  a  drainage  district,  the 
State  Engineer,  as  soon  as  practicable,  after  proper  surveys  have  been 
made,  shall  submit  to  the  Board  of  Directors  of  the  district,  plans, 
specifications,  and  estimates  of  the  cost  of  the  works  necessary  in  said 
district,  in  order  to  secure  a  proper  system  of  drainage  therefor." 

After  the  report  of  the  State  Engineer;  as  aforesaid,  is  made,  the 
Board  is  requested  to  adopt,  amend,  or  reject  the  whole  or  any 
portion  of  the  plans  presented,  or  to  refer  them  back  to  the  State 
Engineer  for  further  report.  After  the  adoption  of  plans  and  speci- 
fications, the  Board  is  required  to  advertise  for  thirty  days  for  pro- 
posals before  any  contract  for  work  embraced  in  the  plans  can  be 
let.  This  Board  was  appointed  on  the  tenth  day  of  June  of  the  cur- 
rent year.  The  area  of  the  district  being  so  great,  the  magnitude  of 
the  interests  involved  so  stupendous,  and  the  labor  to  be  performed 
by  the  State  Engineer  so  extensive,  that  although  the  utmost 
diligence  was  exercised  by  that  officer  and  his  assistants,  the  plans 
and  specifications  could  not  be  completed  so  as  to  enable  us  to 
let  contracts  prior  to  the  tenth  day  of  August. 

The  following  reports  of  Wm.  Ham.  Hall,  State  Engineer — and 
furnishing  the  basis  of  our  actions — will,  we  think,  convey  an  ade- 
quate idea  of  the  problem  to  be  solved. 

THE  WORKS  OF  DRAINAGE  FOR  THE  SACRAMENTO  VALLEY. 

SACRAMENTO,  June  25th,  1880. 
Honorable  Board  of  Directors,  Drainage  District  No.  1 : 

GENTLEMEN  :  You  have  been  called  upon  to  carry  forward  such  works  of  drainage  as  may  be 
practicable  and  deemed  necessary  for  the  territory  now  known  as  Drainage  District  No.  1 ,  and 
I,  as  State  Engineer,  am  required  to  proposeplans  for  and  supervise  the  execution  of  these  works. 


The  report  to  the  State  Drainage  Commission. 

The  circumstances  and  views  which  have  led  to  and  governed  in  the  formation  of  this  district, 
are  set  forth  in  a  report  made  by  myself  to  the  State  Board  of  Drainage  Commissioners,  under 
date  of  May  twenty-sixth,  eighteen  hundred  and  eighty,  and  which  has  been  published,  together 
with  a  copy  of  the  record  of  the  minutes  of  the  proceedings  of  that  Board,  had  at  a  meeting 
held  on  the  twenty-eighth  of  May. 

Drainage  District  -ZVb.  1. 

Your  district  embraces  all  of  the  Sacramento  Valley  in  which  it  will  be  necessary,  as  far  as 
can  now  be  seen,  to  execute  works  of  drainage,  except  some  of  the  low  lands  in  the  delta  which 
is  common  to  the  San  Joaquin  as  well  as  the  Sacramento  Kiver. 

The  report  to  the  Legislature. 

In  a  general  way,  the  drainage  of  this  district — the  Sacramento  Valley — has  been  discussed 
by  me  in  Parts  II  and  III  of  my  report  to  the  Legislature,  under  date  of  January  tenth,  eight- 
een hundred  and  eighty.  To  avoid  much  repetition  of  argument  in  detail,  I  shall  herein  only 
briefly  summarize  the  practical  conclusions  at  large  on  this  topic,  and  ask  your  attention  to  the 
papers  referred  to,  for  the  discussions  which  have  led  to  them.  The  broad  'facts  in  the  case  are 
as  follows : 

Facts  concerning  the  rivers. 

First — Generally,  throughout  its  course,  the  channel  of  the  Sacramento  Eiver  as  the  main 
drain,  and  that  of  the  Feather  as  its  chief  auxiliary,  in  their  present  condition,  are  incapable  of 
affording  passage  for  the  waters  of  ordinary  flood  volume  without  subjecting  a  large  portion  of 
the  great  low-land  basins  and  island  swamps  to  inundation. 

Second — The  regimen  of  the  Sacramento  River  is  bad  j  its  channel  is  of  very  uneven  capacity 
in  proportion  to  the  demand  for  waterway,  in  the  succeeding  great  divisions  thereof,  besides 
having  serious  local  obstructions  to  flood  flow. 

Third — These  defects,  general  and  local,  have,  in  a  degree,  always  existed,  but  they  have 
been  largely  developed  of  late  years  from  causes  still  present  or  at  work.  The  detritus  from  the 
mines  is  filling  the  lower  Sacramento  River  and  its  principal  tributaries,  and  an  injudicious 
location  of  levees  has  unduly  limited  the  width  of  flood  waterway  at  important  points  and  for 
long  stretches  of  channel. 

Preservation  of  the  rivers. 

It  is  desired  to  preserve  these  river  channels.  By  the  passage  of  the  law  under  which  we  are 
called  upon  to  act,  the  State  has  signified  her  realization  of  the  importance  of  thus  fostering  the 
interests  more  directly  affected  by  their  deterioration,  as  well  as  those  dependent  upon  the 
causes  which  in  great  measure  produce  this  result. 

The  Act  to  promote  drainage. 

It  is  the  object,  as  I  understand  the  measure,  to  promote  drainage — as  the  title  of  the  Act 
implies — in  accomplishing  which  it  is  necessary  to  do  away,  as  far  as  possible,  with  the  evil 
results  of  the  flow  of  detritus  from  the  mines,  and  to  construct  or  develop  waterway  for  the 
Hoods.  Furthermore,  it  is  expected  that  the  accomplishment  of  this  end  will  improve  the  nav- 
igation of  the  rivers  and  will  facilitate  the  reclamation  of  swamp  lands  in  the  valleys  adjacent, 
because  it  would  be  impossible  to  attain  the  primary  object  without  doing  much  which  will 
tend  towards  those  kindred  thereto. 

GENERAL    DRAINAGE    PLANS. 

Two  general  lines  of  action  for  the  engineering  solution  of  the  river  problems  presented  are 
frequently  brought  forward.  They  rest  respectively  upon  what  may  be  termed  the  Conserva- 
tion and  the  Distribution  theories  of  river  improvement. 

The  Outlet  or  Distribution  treatment. 

To  carry  aivay  the  waters  of  flood,  it  has  been  proposed  to  supplement  the  river  waterway  by 
the  construction  of  an  artificial  channel,  or  channels,  on  the  route  down  the  valley  to  the  bay, 
thus  effecting  a  division  of  the  waters,  and,  according  to  the  arguments  of  the  advocates  of  this 
plan,  producing  a  lowering  of  flood  elevations  and  a  shortening  of  high  water  periods.  This  is 
the  plan,  based  upon  the  theory  that  the  greater  number  of  channels  in  which  the  waters  run, 
the  less  will  be  their  flood  elevations — a  theory  which  I  have  called  the  Distribution  theory, 
because  of  the  distribution  of  the  waters  amongst  several  channels. 

In  the  report  spoken  of,  I  have  discussed  this  plan  of  outlet  canals,  and  have  expressed  the 
opinion  that  it  would  not  afford  the  desired  relief  from  excessive  flood  heights,  but,  on  the  con- 
trary, its  primary  result  would  be  to  bring  about  a  further  deterioration  of  the  channel  of  the 
main  river  and  impair  its  usefulness  as  a  flood-carrying  and  navigable  stream.  I  am  led  to  this 
conclusion  by  the  results  of  experience  had  in  river  improvement  -re,  the  records  of 


which  I  have  examined,  and  by  the  behavior  of  this  stream  itself  under  conditions  observed 
during  the  past  two  years. 

The  conclusion  rests  upon  the  opinion  now  quite  generally  entertained  by  engineers,  and 
based  upon  practical  observation  as  well  as  sound  principles,  that  the  division  of  the  waters  of 
a  sediment-bearing  river  results  in  the  formation  of  bars  in  the  channel  below  the  points  of 
diversion,  and  ultimately  in  the  permanent  contraction  of  the  waterway  in  the  proportion 
which  the  volume  of  water  diverted  bears  to  the  volume  formerly  carried  by  the  channel. 
The  only  exception  to  this  rule  is  to  be  found  within  the  influence  of  heavy  tidal  action,  and 
where  other  conditions  are  present  favorable  to  the  tidal  influence. 

The  Conservation  treatment. 

Holding  this  opinion,  I  have  recommended  the  alternative  course — a  systematic  treatment  of 
the  river  channel  itself  throughout,  with  the  view  of  developing  its  greatest  possible  carrying 
capacity,  and  of  maintaining  it  in  good  navigable  condition.  This  plan  rests  upon  the  idea  that 
the  greater  the  volume  of  water  in  a  channel,  the  less  may  be,  and  generally  is,  its  grade  or 
slope,  and  hence  a  conservation  of  waters  in  a  channel  having  a  movable  bottom  will  tend  to 
reduce  its  slope  and  lower  its  flood  elevations  by  scouring  out  the  bottom  material.  This  I  have 
called  the  Conservation  theory  of  river  improvement. 

The  lower  Sacramento  River  and  its  principal  tributary,  the  Feather,  have  beds  most  readily 
moved  by  the  action  of  the  current,  and  the  upper  Sacramento  has  a  channel  which  can  be 
greatly  improved  by  work  hereafter  to  be  discussed.  Hence  I  have  expressed  the  opinion,  after 
an  examination  and  measurement  in  detail,  that  their  development  can  be  carried  forward  to  a 
stage  at  which  capacity  would  be  afforded  for  the  passage  of  all  ordinary  floods ;  but  I  have  said 
that  the  work  must  be  one  for  a  series  of  years,  and  that  from  the  first,  the  great  supplies  of 
sand  which  are  brought  down  the  mining  torrents,  must  be  prevented  from  entering  the  larger 
streams  of  the  valley. 

A  general  plan  of  operations,  according  to  the  Conservation  treatment,  was  sketched  out  in 
the  report  to  the  Legislature,  heretofore  spoken  of,  and  it  remains  now  to  classify  and  mention 
the  principal  works  which  it  will  be  necessary  to  prosecute,  and  this  I  now  do,  so  far  as  these 
can  be  designated  at  present. 

Some  provisions  in  the  law. 

In  classifying  and  pointing  out  the  works  which  may  be  carried  forward  under  your  direction, 
I  hold  in  view  the  provision  of  the  law  which  stipulates  that  "  all  moneys  raised  *  #  * 
shall  be  used  exclusively  for  the  construction  of  dams  for  impounding  the  debris  from  the 
mines,  *  *  *  and  for  the  rectification  of  river  channels  in  which  said  debris  flows  within 
the  drainage  district,"  etc.  (Sec.  24.) 

This  stipulation  would  seem  to  preclude  the  construction  of  any  such  work  as  a  relief  canal, 
and  the  building  of  levees  for  the  protection  of  lands  from  inundations,  but  it  does  not  prohibit 
the  prosecution  of  any  work  which  may  be  necessary  for  the  impounding  of  debris  or  the  recti- 
fication of  river  channels  in  which  the  debris  flows.  I  hold  that  the  works  hereinafter  desig- 
nated are  necessary  to  effect  these  ends,  within  the  district  whose  drainage  system  you  are  called 
up  on  to  improve,  as  I  will  endeavor  to  show  in  each  case. 

CLASSIFICATION    OF   WORKS. 

Two  general  classes  of  works  must  be  undertaken:  the  first,  to  withhold  the  sands  from  the 
main  stream  and  private  property;  the  second,  to  improve  the  channels  of  those  streams  so  that 
they  will  maintain  themselves,  with  a  small  amount  of  attention,  subsequently,  in  the  best 
possible  condition,  as  flood-carrying  and  navigable  channels.  These  works  may  be  somewhat 
more  definitely  classified  as  follows : 

Arresting  the  flow  of  the  detritus — dams. 

First — Works  calculated  to  check  the  flow  of  sands  into  the  navigable  rivers  from  the  mining 
streams.  These  will  consist  of  dams  composed  of  rough  stone,  brushwood,  and  gravel,  or  a 
combination  of  these  materials,  as  the  case  may  be,  located  and  proportioned  as  may  seem  most 
favorable  in  each  case. 

Structures  of  this  character  should  first  be  projected  where  the  best  conditions  are  presented 
for  the  test  of  their  efficiency  at  a  reasonable  outlay  oi  money.  Other  things  being  equal,  the 
lower  down  such  works  can  be  brought  on  the  tributary  streams,  the  more  certain  they  will  be 
of  accomplishing  their  object,  and  at  small  outlay  of  money;  for  lighter  grades  are  found  upon 
which  to  impound  or  rest  the  materials  stored,  longer  crested  dams  are  possible  (over  which  the 
water  will  pour  to  a  less  depth  and  with  less  force)  and  less  material  will  be  left  below  the  site 
unguarded  or  unrestrained. 

The  Yuba  and  the  Bear  Eivers  present  the  best  opportunities  for  this  class  of  work,  and  the 
localities  where  it  is  most  needed. 

In  a  special  report  to  be  submitted  concerning  each  of  these  streams,  I  will  make  recom- 
mendations and  submit  plans  for  the  works  which  I  deem  advisable  to  undertake  at  once  upon 
them. 


Preventing  the  spread  of  the  detritus — levees. 

Second — Works  calculated  to  guard  against  the  spread  of  the  waters  from  the  mining  streams, 
and  consequent  destruction  of  the  channels  in  which  they  flow. 

These  Avill  consist  of  levees,  and  those  already  in  existence  should  be  strengthened,  r 
or  protected  from  erosion,  as  may  be  necessary  in  each  case,  or  new  levees  may  be  constructed 
where  none  are  now  in  existence  or  the  old  ones  are  not  worth  adhering  to. 

The  law  provides  that  such  works  as  are  necessary  for  the  rectification  of  the  river  channels 
in  which  said  debris  flows,  may  be  constructed.  Levees  on  each  side  of  such  streams  as  the 
Yuba  and  Bear  Rivers,  for  instance,  may  be  necessary  to  prevent  the  spread  of  their  waters. 
Xo\v  the  spreading  of  these  waters  results  in  the  deposit  of  their  sediment  and  the  obliteration 
of  the  river  channels.  It  is  necessary,  therefore,  in  order  to  rectify  these  channels,  that  the 
-  be  not  allowed  to  spread,  hence  levees  are  necessary;  and  hence,  I  presume,  you  will 
undertake  this  class  of  work. 

Again,  the  Yuba  and  Bear  River  regions  present  the  theater  of  most  needed  action,  though 
alon--  the  shores  of  the  Feather,  also,  as  well  as  on  the  lower  course  of  the  American,  existing 
levees  must  be  maintained,  if  proper  control  is  to  be  exercised  over  their  waters,  and  the  river 
channels  preserved  or  improved.  In  a  special  report  concerning  work  which  should  be  under- 
taken this  season,  I  will  speak  more  definitely  of  this  subject. 

Checking  the  shoaling  of  the  main  rivers. 

Third — Works  calculated  to  guard  against  the  further  deterioration  of  the  channels  of  the 
larger  rivers,  and  exert  an  influence  towards  their  complete  rectification. 

These  will  have  for  their  immediate  objects,  (1st),  the  prevention  of  heavy  bank  caving,  except 
where  such  may  be  desirable  to  effect  some  beneficial  change  in  the  stream  alignment :  and  (2d), 
the  closing,  or  partial  closing,  of  all  deep  channels  of  escape  for  water  from  the  main  stream 
(such  as  the  crevasses  through  the  bank  of  the  Sacramento  River  below  Knight's  Landing  to 
Sacramento  City),  so  far  as  these  can  be  closed  without  causing  other  ruptures  and  the  creation 
of  other,  lines  of  overflow. 

Bank  caving — spur  dikes  and  revetement. 

The  first  one  of  the  objects  just  mentioned,  is  to  be  attained  by  the  construction  of  spur  dikes 
of  brush,  stone,  gravel,  sand-boxes,  or  piling,  or  a  combination  of  some  of  these,  to  deflect  the 
current  from  the  bank  attacked,  and  create  deposits  for  new  bank  lines.  The  Sacramento  River 
above  Colusa  presents  the  field  where  it  will  be  most  necessary  to  conduct  this  class  of  work,  for 
there  are  a  number  of  points  where  the  river  channel  is  of  exceedingly  bad  trend,  owing  to  this 
caving  of  banks,  and  radical  changes  of  the  channel  are  threatened  to  the  detriment  of  its  uni- 
form regimen  as  a  whole,  and  consequent  defeat  of  its  rectifications — a  leading  object  of  the 
whole  measure. 

Deep  outlets — gradual  closure,  overfloiv  weir*. 

The  second  object  of  this  class  of  work  is  to  be  attained  by  entirely  closing  the  breaks  in 
existing  levees,  so  far  as  it  is  safe  so  to  do,  with  earth  embankments,  and  by  partially  closing 
the  remaining  openings — the  deeper  cuts,  at  least — with  structures  of  brush,  timber,  and  gravel 
or  stone,  over  which  the  water  may  pour,  when  it  reaches  a  certain  safe  flood  elevation,  without 
damage  to  the  structure  itself. 

I  consider  these  overflow  weirs  an  essential  feature  of  the  plan  of  improvement  proposed,  for 
the  river  from  Knight's  Landing  to  Sacramento  City,  and  it  may  be  necessary  to  apply  them 
elsewhere  along  its  course  also.  If  there  were  means  enough  at  command  to  construct  at  once 
such  strong  and  large  levees  along  the  river,  and  to  do  such  other  work  as  would  facilitate  it- 
scouring  out  and  rectification,  by  the  holding  of  all  flood  water,  then  the  weirs  might  be  dis- 
i  with.  But  this  would  necessitate  an  outlay  beyond  the  means  at  all  likely  to  be  at  your 
disposal,  and  as  the  water  will  undoubtedly  escape  during  floods  at  various  points  for  some  time 
to  come,  I  propose  that  it  shall  find  passage  at  such  points  and  in  such  manner  as  will  do  least 
harm,  and  only  at  such  times  as  the  river  channel  may  not  be  able  to  carry  all  presented  to  it. 

Concerning  the  extent  of  this  class  of  work  to  be  done,  the  location  and  character  of  construc- 
tion for  the  proposed  weirs,  I  will  shortly  submit  a  special  report  for  your  consideration. 

Promoting  the  deepening  of  the  main  rivers.    • 

Fourth — Works  calculated  to  cause  the  removal  of  bars  in  the  river,  where  they  exercise  an 
unfavorable  influence  upon  the  uniformity  of  its  capacity,  and  thus  prevent  general  deepening 
by  the  scouring  action  of  its  current. 

Several  notable  bars  of  this  character  and  effect  exist  in  the  Sacramento  River  below  the 
mouth  of  the  J-Y;ither,  and  they  are  found,  as  is  usual  in  such  cases,  where  the  bank  lines  are 
far  apart,  or  where  some  irregularities  of  alignment  in  the  banks  exist  and  cause  a  check  or 
eddy  in  the  current  and  a  deposit  of  sand  as  a  result. 

Removal  of  bars — spur  dikes,  parallel  dikes. 

Their  removal  is  to  be  accomplished  by  the  construction  of  spur  dikes,  or  perhaps  similar 
works  parallel  to  the  current — according  to  the  circumstances  in  each  case — of  brush,  stone, 


gravel,  or  timber  piling,  or  a  combination  of  these,  in  such  manner  as  to  cause  a  concentration 
of  the  current  upon  a  judicious  alignment,  by  contracting  the  channel  to  its  normal  width, 
and  guiding  the  water  in  such  narrowed  channel  up  to  an  elevation  equivalent  to  a  low  flood 
.stage. 

I  may  say  here,  by  way  of  parenthesis,  that  dredging  may  be  required  in  some  of  the  bars, 
but  this  result  is  not  expected  generally. 

As  in  the  case  of  the  last  mentioned  class  of  works,  these  constitute,  in  my  opinion  at  least, 
a  most  important  feature  in  the  plans  to  rectify  the  channel  of  the  river,  and,  as  their  position 
in  this  enumeration  implies,  should  be  carried  forward  before  the  final  and  completed  effort  is 
made  to  force  scouring  action  by  altogether  confining  the  flood  waters ;  because  a  condition  of 
channel  approximating  a  perfect  regimen  for  the  river  is  essential  to  success  in  confining  its 
flood  waters,  and  to  approach  such  a  condition  local  obstructions  must  be  removed. 

Correcting  the  alignment  of  the  main  rivers. 

Fifth — Works  calculated  to  straighten  the  river  channel  where,  by  reason  of  sudden  and 
irregular  turns  or  bends,  a  serious  check  is  given  to  flood  movements,  and  where  the  slope  or 
grade  of  the  country  is  less  than  that  through  which  the  river  generally  courses. 

Under  the  proper  circumstances  a  channel  may  be  benefited  in  this  way  by  making  sudden 
and  sharp  bends  less  abrupt  and  angular,  or  by  opening  a  new  channel  through  behind  such  a 
sinuosity  of  the  river  course,  which  latter  works  are  termed  cut-offs. 

Where  a  bend  is  very  abrupt  it  may  be  made  less  so.  Training  the  current  against  it  by  the 
use  of  spur  dikes  constructed  on  the  opposite  shore  above,  crowding  the  current  out  of  the 
opposite  bay  by  the  continuation  of  the  series  of  spur  dikes  from  above  down  into  it,  and  blow- 
ing down  the  point  from  time  to  time  to  be  washed  away,  as  may  be  necessary,  will  accomplish 
this  result. 

Cid-offs —  Upper  Sacramento  River. 

To  cause  the  complete  elimination  of  a  bend  from  the  course  of  the  channel,  cut-offs  are 
made  by  clearing  the  path  of  the  proposed  new  channel,  cutting  out  a  canal  down  to  near  low 
water  mark  upon  its  route,  to  a  width  of  one  tenth  to  one  fifth  that  of  the  proposed  channel, 
and  forcing  the  currents  of  floods  to  enter  the  cut  by  a  proper  arrangement  of  spur  dikes  or 
other  guiding  works  if  it  be  necessary,  and  from  time  to  time  gradually  closing  the  old  channel 
as  the  new  one  becomes  efficient  by  washing  out. 

The  Sacramento  River,  between  Colusa  and  Butte  Slough  and  the  mouth  of  Feather  River,  is 
a  very  tortuous  stream,  and  narrow  in  proportion  to  its  dimensions  above  and  below.  The 
grade  of  the  country  through  which  it  flows  for  this  division  is  much  less  than  that  above.  Its 
capacity  is  much  less  than  that  of  the  divisions  above  and  below  under  existing  circumstances, 
and  this  is  largely  occasioned  by  excessive  bend  resistance  due  to  the  sudden  turns  in  its  chan- 
nel and  general  tortuous  course. 

To  bring  the  river  to  a  good  regimen  it  will  be  necessary,  in  my  opinion,  to  diminish  the 
abruptness  of  the  most  acute  turns  in  this  part  of  the  channel,  and  shorten  it  also,  by  making 
some  cut-offs.  These  can  be  carried  out  at  a  reasonable  outlay  of  money,  in  a  number  of 
instances. 

Prevention  of  cut-offs —  Upper  Sacramento  River. 

While  it  is  necessary  that  the  river's  course  should  be  straightened  through  the  divisions  from 
Butte  Slough  to  the  mouth  of  Feather,  I  hold  that  above  Butte  Slough,  where  the  formation  of 
cut-offs  is  most  easy,  and  where  they  do  occur  naturally  sometimes,  all  straightening  of  the 
channel  should  be  prevented,  because  the  river  is  already  of  much  greater  grade  and  cross  sec- 
tional dimensions  than  it  is  in  the  division^iext  below,  where  it  is  necessary,  by  making  cuts 
and  the  other  works  spoken  of,  to  increajjBp^  carrying  capacity  and  thus  accommodate  the 
floods  which  are  passed  through  the  channdl'kbove. 

Cut-offs — Lower  Sacramento  River. 

Besides  the  points  in  the  division  mentioned  from  Butte  Slough  to  Feather  River,  the  only 
other  locality  where  the  cut-off  treatment  is  admissible  on  the  Sacramento  River,  is  at  the  upper 
end  of  Steamboat  Slough,  where  it  is  desirable  to  open  up  a  new  head  for  that  channel,  in  the 
process  of  making  it  the  principal  line  of  escape  for  the  flood  waters.  This  subject  is  quite  fully 
discussed  in  my  report  to  the  Legislature,  and  I  will  not  say  more  upon  it  until  I  present  the 
details  in  a  special  paper. 

Forcing  the  scouring  and  enlargement  of  the  main  rivers. 

Sixth — Works  calculated  to  confine  the  waters  of  the  river  to  its  channel  and  cause  an  enlarge- 
ment thereof  by  the  scouring  action  thus  brought  about. 

_  These  works,  of  course,  are  levees,  a  complete  system  of  which,  from  the  highest  point  on  the 
river  where  its  waters  escape  into  the  back  basins  to  the  point  where  full  tidal  action  is  met  at 
the  foot  of  Grand  Island,  is  essential,  in  my  opinion,  to  success  in  the  work  of  rectifying  its 
channel  and  its  final  maintenance  in  an  efficient  and  serviceable  condition  as  a  line  of  flood 
escape  and  a  navigable  thoroughfare. 


Concentration  of  icaters. 

That  the  concentration  and  deepening  of  running  water  does  increase  its  power  to  transport 
sediment,  and  thus  bring  about  an  enlargement  of  its  channel,  if  the  bed  and  banks  thereof  ;i  re 
of  a  character  to  be  at  all  readily  moved,  engineers  and  others  who  study  such  matters  are  well 
agreed. 

The  confining  of  a  greater  body  of  water  over  the  bed  of  the  Sacramento  River  will  undoubt- 
edly cause  its  enlargement  by  the  process  referred  to:  and  if  local  obstructions  are  removed  in 
the  manner  heretofore  spoken  of  or  in  any  manner  which  may  be  necessary,  this  enlargement 
will  go  on  so  long  as  the  waters  are  held  in  and  the  bottom  is  found  to  be  of  the  character 
known  to  exist  generally  throughout  the  lower  river,  until  the  stream  is  much  increased  over 
its  present  dimensions:  fii-oridc'l .  that  the  extraordinary  flow  of  sands  by  which  the  waters  are 
now  overloaded  is  checked  in  the  mining  tributaries. 

The  levee  system. 

It  is  frequently  urged  in  argument  against  the  levee  system  of  river  improvement,  that  the 
prevention  of  overflow  causes  the  rapid  elevations  of  the  stream's  bed  as  compared  to  the  banks 
and  back  lands  upon  which  the  waters  are  prevented  from  spreading  their  sediments,  and  thus 
finally  results  in  the  overthrow  of  the  levees,  destruction  of  the  lands,  and  injury  to  the  river 
itself. 

Although  in  the  course  of  ages  this  result  might,  under  the  natural  order  of  things,  have 
been  brought  about  by  leveeing  the  Sacramento  River,  it  is  certainly  a  question  of  much  less 
time,  under  existing  circumstances,  when  the  channel  below  the  mouth  of  Feather  River  will 
be  destroyed,  if  the  whole  river  is  not  treated  by  the  levee  system ;  and  as  for  the  back  lands,, 
they  can  be  no  worse  off  than  they  are  now  in  any  event. 

Deterioration  of  the  Sacramento  River. 

This  river  channel  is  being  destroyed  by  the  sands  which  are  rolled  along  its  bottom,  not  by 
the  fine  sediments  which  are  carried  in  suspension  by  its  waters,  and  which  only  would  be 
carried  in  large  quantities  out  of  it  upon  the  back  lands,  if  the  levee  Avere  obliterated. 

The  escape  of  waters  from  the  channel  would  not  relieve  it  from  the  charge  of  solid  matter 
which  it  annually  receives,  but  would  simply  cause  the  permanent  lodgment  of  that  matter 
therein,  whereas,  by  the  confinement  of  its  waters  alone  can  the  conditions  be  produced  under 
which  this  detritus  may  be  carried  forward  to  the  flats  and  marshes  of  Suisun  Bay,  where  it 
will  do  less  harm,  for  many  years  to  come,  than  where  it  is  lodging  now. 

We  have  had  the  low-water  plane  of  this  river  raised  two,  three,  four,  and  even  five  feet 
during  the  past  twenty  years.  Such  a  rapid  change  was  never  heard  of  before  in  the  history  of 
other  large  rivers,  and  where  the  levee  system,  too,  had  equal  scope  for  action.  The  bed  of  the 
Po,  a  river  completely  leveed,  and  whose  waters  are  highly  charged  with  sediment,  has  not  been 
raised  so  much  during  the  period  of  its  recorded  history.  The  levees  of  the  Po  may  have 
caused  a  relative  rise  of  several  feet  in  its  bed  over  that  of  its  banks  during  the  past  two- 
centuries,  and  so  the  levees  of  the  Sacramento  may  ultimately  have  that  effect.  But  the  first 
effect  of  a  complete  levee  system  on  this  river,  when  it  is  brought  to  a  good  regimen  and  the 
flow  of  sands  stopped,  will  be  to  cause  a  great  scouring  out  of  its  bed  and  enlargement  of  its 
channel,  and  thus  lower  both  its  flood  and  low  water  planes,  and  many  years  will  elapse  before 
the  effect  of  the  levees  in  causing  a  contrary  action  will  be  felt. 


The  Mississippi  and  the  Sacramento. 

A  river  such  as  the  Mississippi,  whose  great  defect  in  capacity  is  due  to  the  very  shoal  bars 
caused  by  caving  banks  and  great  irregulari^Hkwidth,  can  have  its  wateiiine  sufficiently 
lowered  by  the  simple  scouring  out  of  these  slxWfiWTO  carry  its  floods  between  banks  without  a 
levee  system  as  a  necessary  part  of  the  plan, 

Not  so.  however,  with  the  Sacramento.  We  must  remember  that  such  is  not  the  principal 
cause  of  deficient  capacity  in  our  river.  Its  banks  arc  quite  stable  where  the  capacity  is  small : 
but  few  shoals  exist  to  be  removed,  and  these,  although  their  continued  presence  wolild  prevent 
a  general  improvement  of  the  channel,  are  not  themselves  the  principal  cause  of  its  inefiiciency. 

The  Mississippi  River,  with  a  flood  discharge  of  one  million  two  hundred  thousand  to  one 
million  four  hundred  thousand  cubic  feet  per  second  due  to  it,  carries  over  or  in  its  main  bed 
from  five  sixths  to  nine  tenths  of  its  waters,  losing  one  sixth  to  one  tenth  only  into  tin-  swamps 
at  high  flood  stage. 

The  Sacramento  River,  between  Butte  Slough  and  the  mouth  of  Feather  River,  with  a  flood 
discharge  of  eighty  thousand  cubic  feet  per  second  due  to  it,  carries  through  only  thirty  thou- 
sand, having  lo.-t.  into  the  back  basins  on  its  course  nearly  two  thirds  of  its  waters.  There  is 
no  considerable  obstruction  to  flood  flow  from  shoals  in  this  part  of  the  river.  The  channel  is 
narrow,  has  firm  banks,  and  is  exceedingly  crooked. 

The  floods  rise  to  their  maximum  height  in  the  upper  portion  of  this  division  next  below 
Butte  Slough,  and  overtop  levees  three  or  four  feet  in  height  before  the  water  is  bank  high  at 
Knight's  Landing,  twenty  or  thirty  miles  below. 


Defects  of  the  Sacramento  River. 

As  before  remarked,  these  divisions  of  the  Sacramento  River — from  Butte  Slough  to  the 
month  of  Feather  River — are  in  need  of  something  more  than  the  sweeping  out  of  shoals.  The 
channel  must  be  straightened  and  heavily  leveed  to  facilitate  and  force  its  enlargement 
throughout. 

This  river  is  naturally  too  small  for  the  amount  of  water  that  is  presented  to  it  generally 
throughout  its  course,  because,  for  ages  past,  so  large  a  portion  of  its  volume,  at  time  of  flood, 
has,  from  local  causes,  escaped  into  the  back  basins,,  that  the  channel  way  has  become  con- 
tracted. 'The  proof  of  this  action  is  found  in  the  fact  that  below  every  escape  channel  of  note, 
all  along  its  course,  there  is  a  radical  diminution  of  average  cross  sectional  area;  and  further- 
more, as  the  water  has  escaped  gradually  over  the  banks  all  along,  there  is  a  gradual  diminu- 
tion in  width  found  in  going  down  stream  through  each  grand  division  of  the  river,  from  one 
large  outlet  or  tributary  to  the  next  below,  until  we  arrive  at  the  region  below  Grand  Island, 
where  the  tide  has  full  sway  and  its  flow  regulates,  in  a  great  measure,  the  width  and  depth. 

The  popular  idea  of  filling  the  low  basins. 

We  have  frequently  heard  that  the  Sacramento  River  should  be  allowed  to  overflow  its  banks 
so  that  the  low  basins  might  become  filled  up.  It  may  be  remarked  here,  with  propriety,  that 
these  basins  would  not  fill  up  unless  the  river  deserted  its  present  course  and  occupied  them  in 
turn  as  channel  ways.  The  river  bed  and  its  immediate  banks  were,  naturally  built  higher 
than  the  basins  before  the  advance  of  the  sands  from  the  mines,  and  they  would  probably  con- 
tinue to  rise  more  rapidly  than  the  basins,  for  the  sediments  brought  down  by  the  waters  of 
such  streams  are,  for  the  most  part,  deposited  immediately  on  the  bank  which  is  naturally 
overflowed,  and  it  is  only  when'the  waters  escape  with  force  through  a  crevasse  that  the  solid 
matter  is  carried  far  back  into  the  basin  and  elevates  it  commensurate  with  the  rate  of  eleva- 
tion of  the  river  bank  and  bed. 

The  true  idea  of  this  matter. 

Thus  the  only  way  to  equalize  the  land  elevation  back  from  the  river  to  that  along  its  bank 
would  have  been  to  levee  the  river  and  force  streams  of  water  back  to  the  basin  through  chan- 
nels, and  there  cause  the  deposit  of  their  sediments. 

But  as  the  river  has  received  this  charge  of  sand,  which  cannot  thus  be  sluiced  out  on  to  the 
low  lands,  to  any  great  extent  at  least,  and  as  the  preservation  of  the  river  is  the  object  in  view 
and  not  the  filling  up  of  the  basins,  there  is  still  greater  necessity  now  for  a  complete  confine- 
ment of  the  waters  between  levees. 

I  refer  in  the  above  to  the  Sacramento  River  below  the  mouth  of  the  Feather,  and  presume 
that  the  object  is  to  preserve  and  improve  its  channel.  That  this  river  itself  could  be  turned 
into  the  basin  which  flanks  it  on  the  west,  and' there  be  made  to  deposit  its  sediment  for  some 
years  to  come,  is  quite  certain;  but  the  result  would  be  destruction  to  the  present  channel, 
and  the  future  would  be  altogether  problematical  with  the  land  and  cities  below  the  point  of 
turning. 

Necessity  for  a  levee  system  on  the  Sacramento  and  Feather  Rivers. 

After  the  other  works  which  have  been  hereinbefore  spoken  of  have  been  well  taken  in  hand, 
the  general  leveeing  of  the  river  should  begin.  This  work  should  be  prosecuted  from  the  upper 
portion  of  the  stream  downwards,  in  the  reverse  direction  from  that  of  the  other  principal 
improvements.  The  channel  itself  should  be  cleared  of  local  obstructions  from  the  lower  end 
up,  to  bring  about  the  conditions  under  which  it  will  profit  by  the  effects  of  leveeing  and  con- 
fining its  waters,  and  then  this  forcing  should  commence  at  the  upper  end. 

The  first  leveeing  that  is  undertaken,  therefore,  other  than  that  necessary  to  equalize  banks 
along  the  river  generally  and  close  gaps  as  before  explained,  should  be  from  Chico  Creek  to 
Butte  Slough. 

In  my  report  to  the  Legislature,  already  referred  to,  will  be  found  some  general  suggestions 
for  the  disposition  of  the  levees  along  this  part  of  the  river  as  well  as  through  other  divisions. 
In  special  reports  on  the  subject,  hereafter  to  be  submitted,  the  matter  will  be  treated  more  in 
detail. 

OTHER   "WORKS. 

I  have  now  classified  the  works  which  it  is  essential  should  be  carried  forward  for  the  rectifi- 
cation of  the  main  rivers  of  this  valley,  and  have  inu;cated,  in  a  general  way,  the  localities 
where  they  are  to  be  undertaken,  and  the*order  of  their  proper  progress. 

In  addition  to  these  it  may  be  necessary,  as  time  goes  on,  to  execute  other  works,  some  of 
them  of  considerable  magnitude,  in  order  to  relieve  the  large  rivers  of  the  load  of  silt  which  is 
brought  to  them,  and  insure  their  continued  improvement,  as  well  as  to  otherwise  dispose  of 
flood  waters,  if  the  drainage  of  the  valley  is  to  be'made  complete. 

Diversion  of  tributaries  to  deposit  detritus. 

For  instance,  although  the  Sacramento  River  itself  cannot  with  propriety  and  safety  be 
turned  into  any  of  the  low  basins  which  flank  it,  as  a  means  of  disposing  of  the  sands,  the  case 


10 

may  be  different  with  several  of  its  tributaries,  notably  the  American  and  the  Bear  Rivers,  which 
be  led  to  deposit  their  .-unds  in  the  low  basin  lying  between  the  two  on  the  cast  side  of 
•raiiic'.ito.  Indeed,  they  both  do  so  now  in  a  degree,  and  during  the  past  season  the  Bear 
has  shown  a  strong  di.-p<»siiion  to  turn  to  the  south  altogether  and  desert  its  former  mouth 

into  the  Feather  for  an  outlet  into  the  basin  mentioned. 

An  examination  in  detail  of  the  practicability  and  cost  of  thus  disposing  of  the  sands  of  these 

two  troublesome  tributaries  will  be  made  under  my  direction  during  the  present  season,  and 

will  form  the  subject  of  a  special  report  at  a  later  date. 

of  the  Coast  Range  Creek  flood  waters. 

And  still  again,  the  disposal  of  the  waters  of  Putah  and  Cache  Creeks,  which  flow  into  the 
Yolo  basin,  is  an  essential  part  of  a  complete  system  of  drainage  for  this  district,  if  not  abso- 
lutely a  necessnry  operation  in  the  rectification  of  the  main  river  channels.  This  project  is 
~ed  in  Part  II  of  my  report  to  the  Legislature,  and  I  invite  your  attention  to  the  views 
there  advanced. 

In  my  opinion,  these  creek  waters  should  be  turned  through  a  high  grade  canal  over  the 
Montezuma  hills,  to  an  independent  outfall  in  the  slough  north  of  Suisun  Bay.  By  this  means 
only  can  the  great  accumulation  of  water  in  the  Yolo  basin  be  prevented,  the  levees  of  the 
river  be  maintained  and  rendered  efficient  at  reasonable  outlay,  and  the  success  of  the  drainage 
of  the  valley  be  rendered  complete. 

GENERAL  REVIEW  OF  THE  RIVER  TREATMENT  PROPOSED. 

Glancing  over  what  has  been  said  in  this  report,  and  in  that  made  to  the  Legislature  in  Jan- 
uary, it  will  be  found  that  I  have  advocated  the  Conservation  treatment  in  the  improvement  of 
the  main  rivers  of  this  valley;  that  I  propose  to  bring  the  channels  to  a  good  regimen — even 
capacity  to  do  the  duty  required — by  straightening  them  where  necessary  and  admissible,  by 
scouring  out  shoals  where  these  exist,  particularly  in  the  lower  river,  by  training  the  current  to 
destroy  great  eddies,  and  by  preventing  the  local  escape  of  flood  waters"  in  large  volume,  and  to 
supplement  its  present  capacity  by  raising  levees  which  will  themselves  form  a  larger  channel- 
way  and  force  the  enlargement  of  that  already  existing  by  the  scouring  action  of  the  confined 
waters. 

A  system  of  levees  necessary. 

And  I  hold  that  a  levee  system  is  necessary  to  preserve  the  existing  channels  of  the  Sacra- 
mento and  Feather  Rivers  and  to  accomplish  their  rectification. 

If  these  channels  were  more  nearly  proportioned  in  size  to  the.  volume  of  water  which  comes 
•down  the  valley,  and  like  many  other  streams,  were  deficient  in  capacity  merely  because  of 
local  obstructions,  such  as  extended  bars,  their  rectification  could  be  accomplished  without  the 
levees.  But,  as  has  been  shown,  such  is  not  the  case,  and  we  can  only  accomplish  the  object 
through  'the  medium  of  a  levee  system. 

Could  we  sweep  out  of  existence  all  levees  now  standing  along  the  Sacramento  and  Feather 
Rivers,  the  floods  would  spread  into  the  back  basins  at  many  places,  and  there,  finding  shorter 
lines  of  escape  from  point  to  point  on  the  rivers,  would  pursue  these  routes,  robbing  the  channel 
in  some  of  its  divisions  of  the  waters  due  to  it  and  necessary  to  preserve  its  size,  and  gorging  the 
channel  with  more  than  it  could  carry  at  other  points. 

The  result  would  be  the  contraction  of  the  existing  channels  in  some  of  their  divisions  and 
the  formation  of  new  outlets  or  the  enlargement  of  those  already  in  existence,  until,  by  the 
action  of  some  great  flood,  the  channel  of  the  river  itself  would  change  materially.  This  is 
just  what  was  going  on  before  leveeing  commenced  here. 

Xow  there  are  levees  over  four  fifths  of  the  route  of  the  river  within  the  district  where  their 
waters  could  naturally  escape  into  the  back  basins.  These  levees  are  of  very  uneven  height, 
•me  of  them  badly  located.  If  they  are  left  in  their  present  condition,  and  an  attempt  be 
made  to  improve  the  channels,  what  will  be  the  result?  Manifestly  a  more  unfavorable  one 
than  if  there  were  no  levees  at  all.  The  waters  would  escape  where  the  levees  are  weal; 
where  there  are  none,  and  in  large  volume  locally,  as  they  do  now  in  reality,  and  the  river 
•could  not  be  brought  to  a  good  regimen,  for  there  would  be  no  control  of  the  floods,  which 
would  leave  the  channel  or  return  to  it  whenever  opportunity  offered;  and  without  a  nearly 
perfect  regimen  we  can  hope  for  no  general  improvement  in  the  channel. 

The  obj.'ct  is  to  prevent  the  further  deterioration  of  these  rivers  and  to  improve  them. 

The  detritus  lodged  in  the  river  beds  must  be  disposed  of,  and  the  channels  otherwise  rectified 
and  enlarged.  It  is  absurd  to  talk  of  dredging  them  all  out,  as  has  been  publicly  suggested. 
Twenty  millions  of  dollars  would  not  more  than  free  the  two  rivers  by  tiiis  process. 

A  portion  of  the  sediment  should  be  used  in  levee  construction,  but  the  great  mass  must,  be 
swept  out  by  the  river  currents.  This  can  only  be  accomplished  by  putting  the  rivers  in  condi- 
tion to  facilitate  this  action,  and  by  a  control  of  all  ordinary  floods;  and  a  system  of  good 
strong  levees  is  essential  for  this  treatment. 

.1  system  as  is  n.-c-'s.-ary  for  this  purpose,  however,  will  not  effect  the  complete  reclama- 
tion of  all  the  swamp  lands  in  the  great  basins  of  the  district,  but  of  course  would  do  much 
toward  that  end.  There  would  still  be  a  necessity  for  organized  action  in  the  reclamation  dis- 
tricts which  must  continue  to  exist  and  each  labor  in  its  own  behalf,  while  the  drainage  work 


11 

will  be  for  the  common  good  of  all.  This  subject  is  more  fully  touched  upon  in  a  report  sub- 
mitted by  me  to  the  State  Board  of  Drainage  Commissioners,  under  date  of  the  twenty-sixth  of 
May,  and  to  that  paper  I  ask  your  attention. 

AN    ESTIMATE    OF    COST. 

Concerning  the  probable  cost  of  the  works  herein  outlined,  I  can  only  at  this  time  give  a 
rough  idea.  To  construct  levees  of  proper  size  entirely  anew  along  the  Feather  and  Sacramento 
Eivers  where  necessary  within  this  district,  would  cost  in  the  neighborhood  of  three  millions  of 
dollars. 

It  may  be  said  that  one  third  of  this  work  has  been  accomplished  efficiently  thus  far,  so  that 
it  couM  be  made  a  part  of  the  work  of  the  future.  We  have  then  a  balance  of  two  millions  of 
dollars  to  be  expended  on  this  class  of  work. 

An  estimate  of  what  might  be  expended  to  advantage  within  the  next  ten  years  may  be 
made,  as  follows : 

Levee  work $2,000,000 

Channel  corrections,  etc 2;000,000 

Storing  sands 1,000,000 

$5,000,000 

Fully  one  half  of  this  work  is  such  as  the  general  government  might  possibly  undertake  for 
the  preservation  and  improvement  of  the  rivers  as  navigable  streams,  but  it  must  be  bimight 
forward  in  its  order  with  the  other  works,  and  cannot  be  left  behind,  else  the  whole  will  be  a 
failure. 

The  work  should  be  so  carried  on  as  to  diminish  the  time  of  execution  as  much  as  possible; 
there  would  be  economy  in  such  a  course,  for  they  will  undoubtedly  cost  more  unless  put  in 
final  condition  as  fast  as  natural  action  will  permit. 

Supposing  the  five  millions  of  dollars  were  expended  during  the  next  ten  years,  I  estimate 
that  the  cost  of  maintenance  would  be  about  two  hundred  thousand  dollars  per  annum  after 
that  period,  half  of /which  would  be  for  storage  of  sands  and  half  for  river  works;  and  the 
general  government  might  be  expected  to  bear  half  of  the  expense  if  it  pursues  its  present 
policy  in  river  works. 

The  maintenance  of  levees,  while  properly  remaining  under  the  direction  of  the  Drainage 
District  Boards,  should  ultimately  be  paid  for  by  the  lands  thus  protected  from  inundation,  and 
thus  the  State's  share  of  the  expense  of  maintaining  her  rivers  in  good  condition  will,  in  the 
future,  be  reduced  to  a  small  amount. 

Very  respectfully  submitted.  WM.  H.  HALL, 

State  Engineer. 


EEPOET   ON   DAMS   FOE  THE  STOEAGE   OF   MINING  DETEITUS   ON   THE  YUBA 

AND  BEAE  EIVEES. 

OFFICE  OF  THE  STATE  ENGINEER,  ) 

SACRAMENTO,  July  6,  1880.  J 

To  the  Board  of  Directors  of  Drainage  District  No.  1,  Sacramento,  Cal.  : 

GENTLEMEN:  In  the  matter  of  constructing  dams  for  storing  mining  detritus  on  the  Yuba  and 
Bear  Eivei-s,  I  have  to  report  now  in  general  terms,  and  when  further  examinations  shall  have 
been  made  of  the  several  sites  for  dams  and  storage  ground,  I  will  submit  another  report  con- 
cerning the  same,  and  recommend  the  adoption  of  a  definite  policy  on  each  river. 

Transportation  of  sediment  by  moving  waters. 

The  conditions  in  a  stream  most  favorable  to  the  transportation  of  sediments  by  its  waters  are : 
(1),  that  it  be  deep  in  proportion  to  its  width;  (2),  that  it  be  of  uniform  width  and  grade;  (3)' 
that  its  channel  be  of  good  alignment,  free  from  sudden  bends;  and  (4),  that  the  lines  of  its  cur- 
rents be  not  broken  up  by  obstructions  of  any  kind. 

With  such  conditions,  a  rapid  current,  uniform  in  its  movement  throughout  the  several  suc- 
ceeding reaches  and  divisions  of  the  stream,  with  a  sharply  inclined  vertical  velocity  curve, 
would  be  produced,  and  the  waters  would  have  great  power  to  transport  solid  matter. 

Eeversing  these  conditions  in  any  manner,  the  waters  drop  their  silicious  or  earthy  load  in  a 
degree  proportional  to  the  extent  of  the  reverse  order  produced.  Thus,  sediment  carrying  cur- 
rents may  be  made  to  deposit  their  sand  and  slimes  by  checking  the  velocity,  and  otherwise 
destroying  the  conditions  essential  to  their  transporting  power. 

This  may  be  effected  in  either  one  of  three  ways :  (1),  increasing  the  width  of  the  stream,  thus 
reducing  its  depth  as  a  direct  consequence,  and  indirectly  reducing  it  also  by  causing  the  raising 
of  its  bed  by  deposits  thereon;  (2),  reducing  the  grade" or  slope  of  the  stream  by  changing  its 
alignment,  or  by  raising  its  bed  at  some  point  by  a  dam ;  (3),  breaking  up  the  threads  of  its  cur- 
rent by  the  introduction  of  pervious  or  partial  obstructions  to  its  flow. 


12 

The  Y'.iba  and  Bear  River  deposits. 

The  Yuba  and  Bear  Rivers  have  made  immense  deposits  of  gravel,  sand,  and  slime  above 
their  confluence  with  the  Feather,  because  their  grades  greatly  diminish  as  they  approach  that 
stream,  their  waters  have  overtopped  the  low  banks  and  spread  in  wide  sheets  over  the  adjacent 
bottom  lands,  and  the  den-v-.  gix>wth  of  small  timber  and  brushwood  through  which  thev  were 
made  to  run  broke  up  the  lines  of  their  currents. 

Bepo-its  iii  this  manner  occasioned  at  lower  points,  have  served  to  reduce  the  grade  for  other 
points  above,  and  thus,  there  also,  rilling  has  taken  place:  and  still  again,  in  the  canons  the 
natural  irregularity  of  regimen,  and  the  damming  up  occasioned  by  the  lower  mining  dumps, 
have  made  many  extended  reaches  the  storehouses  of  heavier  detritus. 

Proposed  artificial  deposit  of  detritus. 

Now  it  is  proposed  to  cause  an  increased  deposit  from  the  waters  of  these  streams,  at  such 
points  that  it  will  not  damage  private  property  or  injure  the  navigable  main  drains  below. 

So  far  as  the  currents  of  the  Yuba  and  Bear  Rivers  themselves  are  concerned,  it  matters  not 
whether  they  are  either  restored  or  supplemented  by  other  deep  ones,  so  long  as  the  objects  just 
expressed  are  attained.  Indeed,  the  primary  object  being  to  preserve  and  improve  the  channels 
of  the  main  drains  or  navigable  streams — the  Sacramento  and  Feather  Rivers — it  would  seem 
to  be  advisable  to  avoid  any  immediate  restoration  of  the  channels  of  the  tributaries;  for  mate- 
rials washed  from  them  must  pass  down  into  these  larger  rivers,  and  it  is  important  to  withhold 
all  the  sand  that  can  possibly  be  held  back,  at  least  until  such  time  as  they — the  rivers  below — 
can  have  been  brought  to  a  good  regimen  and  scoured  out. 

In  view  of  this  condition,  I  recommend  that  the  treatment  for  the  Yuba  and  the  Bear  be  such 
as  to  retain  their  channels,  for  years  to  come,  at  least,  somewhat  as  they  now  are,  in  wide  and 
shallow  beds;  and  rather  encourage  further  deposits  upon  the  Band  wastes  already  formed 
(where  this  can  be  done  without  great  damage  to  other  yet  uninjured  property),  than  to  cause 
the  restoration  of  any  deep  channels  through  these  deposits. 

This  treatment  should  be  pursued  until  such  time  as  it  shall  have  been  shown  that  the  sands 
are  stopped  at  higher  points,  and  the  large  rivers  below  are,  in  a  great  measure,  relieved  from 
their  filling. 

Locations  for  and  character  of  dams. 

Within  the  canons  of  the  mountains  through  which  the  Bear  and  Yuba  flow,  it  is  not  possible 
by  any  direct  method  to.widen  the  channels.  This  can  only  be  accomplished  by  building  up 
their  beds  through  the  action  of  dams,  thus  effecting  the  double  object  of  increased  width  and 
decreased  grade  above  each  dam. 

The  subject  of  retaining  the  detritus  by  means  of  stone  dams  within  the  canons  of  the  Yuba 
River  was  discussed  by  me  in  Part  III  of  the  report  to  the  Legislature,  submitted  in  January, 
and  allusion  was  made  to  the  possibility  of  effecting  the  same  end  by  means  of  dams  of  brush 
and  gravel  at  lower  points  on  the  same  streams. 

Further  observation  and  thought  have  convinced  me  that  the  work  should  be  commenced  as 
low  down  on  the  str.-ams  as  the  detritus  can  be  held  safely,  and  that  the  dams  built  must  at  first 
be  of  the  latter  mentioned  <• 

The  sands  stored  at  lower  points  will  themselves  serve,  to  some  extent,  as  dams  for  storage 
••ve;  and  furthermore,  brushwood  is  the  only  material  to  be  had  at  some  of  the 
sites  for  darns,  and  these  structures  must  be  built  of  it  if  at  all. 

A  brush  dam  possesses  the  advantages  of  greater  stability  and  safety  on  soft  or  sandy  founda- 
tions, and  great  cheapness  of  construction. 

A  rock  dam  lias  in  its  favor  the  considerable  advantage  of  the  durability  of  its  material  and 
of  stability  under  great  floods — supposing,  of  course,  its  foundation  to  be  secure. 

M  the  wide  sand  Hats  below  the  canons  proper,  undoubtedly  brush  dams  should  bo 
adopted,  primarily,  at  least;  while  between  the  high  banks  of  the  foothills,  rock  dams,  where 
material  is  abundant,  can  be  most  conveniently  built,  and  would  have  the  advantage  of  per- 
manence to  a  degree  which  should  render  their  ultimate  adoption  advisable. 

Storage  below  the  canons. 

Were  the  sands  stopped  at  the  canon  mouths  on  the  Yuba  and  Bear,  it  would  still  be  neces- 
sary in  preventing  the  channeling  out  at  lower  points  through  the  sand  wastes  above  the 
Feather,  to  lay  in  some  low  brush  dams  or  sills,  as  heretofore  alluded  to,  in  order  that  the^e. 
might  not  be  swept  down  before  the  large  rivers  could  receive  them  safely.  This 
being  the  case,  it  will  be  wise  to  make  these  obstructions  do  the  additional  duty  of  holding  more 
sands  if  possible,  and  hence  at  the  lowest  point  where  this  can  be  done  with  safety,  the  first 
dams  should  be  built. 

All  of  the  sands  which  will  come  down  these  streams  for  several  years  can  be  thus  .- 
!-'lo\v  the  canons  proper,  on  lands  already  covered;  and,  by  an  extension  of  leveeing  work, 
still  greater  storage  capacity  can  be  obtained  over  the  same  superlices. 

Stone  dams  commenced  with  brush. 

Th'  :.-r  of  destruction  to  a  stone  dam  of  the  character  and  for  the  purposes  it  is 

Ernj-MA-ed  to  build  them  on  these  streams,  i>  from   undercutting  at  its  down  stream  edge,  and  in 
uilding  oi  stone  alone  it  is  difficult  and  expensive  to  guard  against  this  action. 


33 

With  brush,  however,  this  difficulty  is  much  more  readily  met,  and  it  is  proposed  to  protect 
the  stone  dams  by  submerged  brush  dams  at  the  down  stream  edges  of  their  aprons.  These 
brush  dams,  by  raising  them  higher,  can  be  made  to  retain  a  large  amount  of  sand  above  them 
before  the  stone  dam  is  commenced,  and  hence,  again,  we  have  sound  arguments  not  only  for 
the  construction  of  the  first  dams  low  down  on  the  streams,  of  brush,  but  for  the  commencement 
of  all  dams  with  that  material. 

THE    STONE    DAMS    PROPOSED. 

It  may  be  well  to  consider  here  for  a  moment  the  principles  upon  which  we  are  to  proceed  in 
the  matter  of  constructing  dams,  both  of  brush  and  of  stone. 

Stone  dams — character  of. 

The  proposed  stone  dams  would  be  massive  structures  of  loose  rubble,  not  coursed  or  hand- 
laid,  but  somewhat  assorted  with  respect  to  size  of  pieces,  as  hereinafter  explained,  with  crests 
ten  to  twenty-five  feet  in  thickness,  and  long  slopes  both  up  and  down  stream. 

For  a  clear  idea  of  the  problem  of  these  stone  dams,  it  is  essential  to  remember  that  they  are 
to  be  for  the  purpose  of  storing  sands,  and  not  water,  and  that  it  will  not  be  necessary,  under  a 
proper  system,  to  have  any  one  of  them  more  than  twenty  feet — say  an  average  of  twelve  feet — 
in  height,  at  any  time,  over  the  bottom  immediately  up  stream  from  it.  Hence  the  dam  be- 
comes but  a  facing  for  an  upper  plane  of  sand;  it  becomes  filled  and  impermeable  only  by 
•degrees,  as  the  sands  rise  upon  it;  and  the  hydrostatic  pressure  behind  it  is  always  limited  to 
that  due  to  but  a  few  feet  in  depth  of  water.  Such  a  dam  is  intended  to  be  added  to  each  year, 
using  the  filling  above  as  a  foundation  for  a  portion  of  each  addition,  until  the  structure  is 
brought  to  the  desired  height  for  its  site  and  becomes  solidified  with  the  filling  against  it. 

Stone  dams—  their  weak  points. 

If  rocks  of  sufficient  size  are  used,  its  destruction  could  only  be  accomplished:  (1),  by  the 
water  finding  a  low  place  in  the  crest,  and  there  concentrating  its  force;  (2),  by  undermining; 
or  (3),  by  flanking  its  ends. 

The  mere  pressure  of  water  or  shock  of  a  flood  could  not  overthrow  a  dam  of  this  kind;  so 
that  its  destruction,  if  ever  accomplished,  could  only  be  gradual,  and  not  a  sudden  catastrophe. 

Ordinary  care  in  construction  and  maintenance,  and  the  use  of  very  large  stone  on  the  crests 
and  down-stream  faces,  would  prevent  damage  from  channeling  down  and  concentration  of 
waters  at  any  point. 

Ordinary  good  construction,  too,  will  insure  against  the  ends  being  flanked  by  the  floods,  for 
the  water  may  be  kept  away  from  the  extreme  ends  of  the  crest,  and  a  good  junction  may  be 
made  with  the  bedrock  in  the  faces  of  the  hills. 

On  the  foundation,  we  have  the  weakest  line  to  guard. 

If  large  rocks — say  twenty  tons  apiece — be  laid  in  a  row  on  the  sands  across  the  bed  of  a  river, 
such  as  the  Yuba  or  the  Bear,  they  will  quickly  disappear — the  sands  from  between  them  will 
scour  out,  the  rocks  will  gradually  drop  into  the  cavities  produced,  and  will  soon  have  dis- 
appeared almost  entirely,  if  not  quite. 

If  the  same  quantity  of  stone,  broken  to  the  size  of  ordinary  river  gravel,  be  placed  in  a  ridge 
across  the  channel  in  a  similar  locality,  it  will  not  be  undermined;  the  top  stones  will  be  swept 
off,  probably,  one  by  one,  by  the  force  of  the  current,  and  the  whole  ridge  flattened  down,  in 
time  possibly  destroyed  by  this  means,  but  it  will  not  be  dropped  out  of  sight,  in  the  sands,  by 
the  action  of  the  current  passing  under  it  from  above.  If  there  should  be  considerable  fall  over 
it,  and  no  apron  or  flat  surface  of  stones  below,  the  sands  would  probably  be  swept  away  from 
it's  down-stream  edge,  and  the  stones  or  gravel  would  be  washed  into  the  cavity  thus  formed. 

Here  we  have  a  picture  of  the  manner  in  which  a  rubble-stone  dam  may  be  undermined, 
either  by  the  water  running  along  upon  the  sands,  by  way  of  the  spaces,  between  the  stones 
that  compose  the  structure,  from  above,  or  by  the  cutting  under  the  lower  edge  of  the  structure 
after  having  passed  over  its  crest. 

Stone  dams  for  storing  detritus— principles  to  be  observed. 

Should  we  imagine  a  dam  built  up  in  thin  layers,  the  material  in  each  succeeding  one  graded 
in  size  somewhat  larger  than  in  the  layer  below — from  the  dimension  of  the  particles  of  sand 
up  to  those  of-  the  great  mass  of  rock  capable  of  withstanding  any  force  of  water  that  can 
possibly  be  brought  to  bear  upon  it — we  would  have  before  us  a  dam  totally  incapable  of 
destruction  by  undermining  from  above,  because  the  interstices  between  the  particles  of  no  one 
layer  would  be  sufficiently  great  to  admit  the  passage  of  a  stream  of  water  strong  enough  to 
wash  out  its  particles  or  those  in  the  layer  next  below. 

In  tbe  construction  of  stone  dams  to'store  the  detritus  on  the  Yuba  and  Bear  Rivers  we  must 
approach  this  condition  in  their  parts;  the  sands  under  the  foundation  must  be  covered  so  that 
the  waters  of  percolation  will  not  wash  them ;  the  rocks  upon  the  crests  must  be  of  such  great 
dimensions  that  the  force  pf  the  water  cannot  move  them,  and  the  pieces  of  the  intervening 
material  must  be  intermediate  in  size. 


14 

t 

Practical  construction  of  stone  dams. 

The  foundation  may  be  secured,  by  first  depositing  layers  of  very  fine  stone  upon  which  to 
build:  or  the  same  object  may  be  attained  by  building  the  stone  dam  upon  a  foundation 
mattress  or  matting  of  small  brush,  with  fine  stone  or  gravel  intermixed. 

Having  secured  the  foundation  from  washing  above,  the  undei'cutting  at  the  toe  must  be 
guarded  against. 

First  of  all,  for  a  considerable  width  below  any  overfall,  there  must  be  an  apron  to  receive 
the  shock  of  the  waters  and  permit  of  their  taking  a  horizontal  direction  in  the  onward  flow, 
before  reaching  the  movable  bottom. 

This  apron,  of  course,  would  be  most  durable  if  constructed  of  stone,  provided  its  under- 
mining were  guarded  against,  and  to  a  stone  dam  there  should  be  a  stone  apron,  though 'one  of 
logs  or  of  brush  and  gravel  might  be  used  safely  for  years. 

The  lower  edge  of  such  an  apron,  of  whatever  material  composed,  unless  it  were  of  very  great 
width  and  the  water  spread  over  it  in  a  very  thin  sheet,  would  be  liable  to  suffer  from  this 
undercutting  influence,  unless  the  transporting  power  of  the  water  were  broken  up  at  that 
point. 

Flowing  over  or  past  a  hard  and  fast  line,  such  as  the  edges  of  a  stone  or  log  apron  would  be, 
water  almost  always  attacks  the  soft  material  adjacent  to  it,  and  cuts  a  hole  or  pit.  On  the 
contrary,  a  windrow  or  driftrow  of  brush,  lodged  in  a  current  so  that  the  waters  partially  pass 
between  the  branches,  causes  a  deposit  of  sediment  and  the  formation  of  a  bar  below,  which 
works  up  to  and  finally  covers  in  the  brush  itself. 

By  a  proper  construction  and  the  use  of  brush  on  this  principle,  with  which  to  finish  the 
lower  edge  of  the  stone  aprons,  not  only  may  their  undercutting  be  prevented,  but  the  sands 
may  be  caused  to  pile  up  where  it  might  be  supposed  they  would  cut  out. 

I  do  not  propose  to  consume  time  and  space  in  citing  instances  where  like  effects  have 
been  artificially  produced  in  engineering  work.  Suffice  it  to  say,  that  the  annals  of  modern 
river  engineering  afford  analagous  examples,  and  the  working  of  the  law  upon  which  the  result 
rests  may  be  observed  in  nature  every  day,  and  in  many  places  upon  our  own  streams. 

I  am  of  the  opinion,  therefore,  that  stone  dams  of  this  character  can  be  put  upon  the  saud 
foundations  in  the  lower  portions  of  and  at  the  mouths  of  the  canons  of  the  Yuba  and  Bear 
Eivers  with  perfect  safety. 

Dams  for  storing  detritus,  and  other  stone  dams. 

I  remark  the  difference  in  principle  upon  which  we  should  proceed  in  laying  the  stone  dams 
here  contemplated,  from  that  followed  in  placing  stone  foundations  for  other  purposes. 

In  the  case  of  the  proposed  rubble  dams,  we  expect  percolation  through  them,  and  only  guard 
against  the  washing  out  of  the  material  below  by  covering  it  in  with  other  material,  the"  nature 
or  arrangement  of  which  will  not  admit  of  the  washing. 

We  have  water  highly  charged  with  silt,  which  it  is  expected  will  deposit  its  load  in  the  dam 
as  the  sands  are  rolled  against  it.  We  are  not  constructing  to  hold  clear  water,  or  to  bear  a 
heavy  load. 

In  stone  foundations  for  a  bridge  or  a  masonry  dam,  the  work  itself  is  intended  to  be  imper- 
meable and  immovable  from  the  commencement;  the  largest  stones  may  be  placed  at  the  bot- 
tom, and  it  is  not  intended  that  they  should  move. 

In  the  case  of  the  proposed  rubble  dams,  although  they  must  be  placed  on  good  sand  and 
gravel  foundations,  and  not  on  quicksand  or  "slickens,"  settlements  which  will  be  utterly 
destructive  to  works  of  the  other  class,  would  not  be  a  serious  circumstance ;  indeed  they  are  to 
be  expected,  and  the  dam's  crest  must  be  brought  up  to  grade  as  well  as  raised,  perhaps,  to 
accomplish  more  storage  each  year. 

Stone,  the  proper  material  for  the  future;  brush,  for  the  present. 

And,  in  view  of  the  fact  that  all  dams  to  be  used  in  storing  this  material  should  be  as  perma- 
nent as  possible,  I  think  the  great  mass  of  it  in  the  future  should  be  stored  above  stone  works. 

But,  considering  what  has  preceded  in  this  paper,  I  am  clearly  of  the  opinion  that  the  work 
should  be  commenced  with  brush  structures,  and  possibly  this  brush  work  can  be  used  in  other 
ways  so  as  greatly  to  cheapen  the  stone  structures,  as  hereafter  suggested. 

THE    BRUSH    DAMS    PROPOSED. 

Concerning  brush  dams  there  is  not  so  much  to  say.  The  illustration  heretofore  cited  of  a 
driftrow  of  brush  lodged  in  a  current,  affords  the  idea  of  the  simplest  form  of  such  a  work,  and  the 
natural  growth  of  brushwood  and  small  timber  over  the  sand  flats  in  Yuba  Eiverand  Bearlliver 
presents  another  excellent  example  of  a  pervious  brush  dam,  which  causes  a  deposit  commenc- 
ing below  it,  by  breaking  up  the  lines  of  the  current,  and  thus  destroying  its  capacity  to  transport 
its  load  of  solid  matter. 

Natural  brush  dams. 

One  cannot  long  study  the  action  of  this  growth  in  the  localities  mentioned,  without  being 
thoroughly  convinced  of  the  efficiency  of  the  brush  dams  which  nature  thus  rears  in  the  way  of 
the  floods'with  their  charges  of  sand. 


15 

It  has  only  to  be  seen  for  the  fact  to  be  appreciated,  that  but  a  small  proportion  of  the  solid 
matter  is  carried  through  such  an  obstruction,  and  that  it  would  only  be  necessary  to  close  the 
channels  intervening  between  the  great  growths  of  young  trees,  by  similar  obstructions,  to 
cause  an  almost  complete  intercepting  of  the  detritus. 

Thus,  were  the  sand-covered  fiats  of  the  Yuba  and  Bear  Rivers  flanked  by  high  plains  or 
levees,  they  might  be  made  to  retain  the  sediment  to  be  brought  down  for  a  number  of  years 
to  come,  by  simply  causing  the- sands  to  rest  upon  them  on  greater  grades,  by  placing  low  per- 
meable brush  dams  at  short  intervals  of  space  in  the  way  of  the  currents,  and  adding  to  them 
from  year  to  year. 

As  it  is,  however,  no  such  banks  exist  very  far  down  into  the  plain;  the  time  has  passed 
when  this  action  could  have  been  availed  of  to  any  great  extent  without  artificially  confining 
the  waters  on  the  sides,  and  for  this  purpose  very  large  levees  must  be  now  constructed,  although 
by  such  means  the  storage  room  below  the  foothills  will  be  increased,  yet  it  is  limited,  and  we 
must  look  forward  to  the  time  when  it  will  be  exhausted.  When  we  can  no  longer  raise  the 
lower  portion  of  the  storage  ground  there  will  be  an  overfall  necessary  at  some  point — the 
lowest  limit  of  the  deep  storage — and  for  that  a  pervious  brush  dam  will  not  suffice. 

There  must  be  a  firm  structure  down  whose  face  water  may  fall,  as  over  a  stone  dam,  without 
washing  out  any  of  the  material  in  or  under  it. 

Impervious  brush  dams. 

Of  gravel  and  brush  or  small  trees,  such  a  dam  can  be  readily  built  to  a  moderate  height. 

The  main  structure,  in  order  that  it  may  be  firmly  held  to  the  sand  and  gravel,  must  be  built 
with  the  tops  of  the  trees  up  stream  with  their  branches  covered  in  and  incorporated  with 
gravel  or  coarse  sand,  by  which  arrangement  also  the  butt  ends  are  placed  down  stream  and 
form  the  overfall  face  and  crest  of  the  dam . 

A  heavy  apron,  immediately  below  the  overfall,  should  be  constructed  in  similar  manner; 
while  to  prevent  the  undercutting  action  from  below,  a  lower  apron  must  be  provided  with  the 
brushy  ends  of  the  trees  down  stream. 

We  would  thus  have  a  dam  as  immovable  as  a  drift  tree  which  lodges  upon  a  sand  bank  and 
forever  forms  a  snag,  unless  removed-by  human  agency. 

Stability  of  brush  dams. 

If  we  consider  the  width  to  which  the  waters  of  the  streams  now  under  discussion  are  spread 
at  the  points  where  it  is  proposed  to  construct  brush  dams,  we  will  realize  how  they  will  be 
robbed  of  their  destructive  force  by  being  led  to  encounter  an  obstacle  such  as  a  dam  in  the  face 
of  the  entire  front  of  their  flow. 

For  instance,  the  extreme  flood  discharge  of  the  Yuba  River  is  about  fifty  thousand  cubic 
feet  per  second,  and  its  ordinary  flood  discharge  does  not  exceed  half  that  amount,  while  its 
usual  discharge  through  the  Winter  and  Spring  is  about  five  thousand  cubic  feet  per  second. 

I  take  the  larger  figure  to  illustrate  the  case :  At  the  De  Guerre  dam  site,  the  shortest  pro- 
posed line  of  construction  for  a  brush  dam,  the  overfall  will  be  about  five  thousand  feet  in 
length.  Fifty  thousand  cubic  feet  of  water  per  second,  running  at  a  speed  of  ten  feet  per  sec- 
ond, will  pass  over  a  crest  five  thousand  feet  long  in  a  sheet  one  foot  deep,  or  running  at  the 
rate  of  five  feet  per  second,  it  would  pass  over  the  five  thousand  foot  crest  two  feet  in  depth. 

In  actual  practice  it  would  run  at  a  rate  according  to  its  velocity  of  approach  to  the  dam, 
which  would  make  it  from  1.3  to  1.7  feet  deep  over  it. 

With  a  stick  to  brace  himself,  a  man  could  almost  wade  across  the  Yuba  River,  on  the  crest 
of  such  a  dam  at  the  time  of  its  greatest  discharge,  and  could  certainly  do  so  at  time  of  ordinary 
flood,  provided  the  dam  was  so  placed  and  constructed  that  the  water  approached  it  with  nearly 
equal  velocity  at  all  points. 

Now,  a  sheet  of  water  a  foot  and  a  half  deep,  moving  at  the  rate  of  seven  feet  per  second, 
represents  about  the  maximum  moving  force  we  have  to  contend  against,  and  under  such  cir- 
cumstances it  will  not  be  a  difficult  task  to  construct  brush  aprons  below  the  dam,  and  so  guard 
them  as  to  insure  against  undermining. 

We  have  examples  of  brush  dams  of  comparatively  slight  construction  in  California  which 
have  long  withstood  the  action  of  water  running  over  them  to  an  equal,  if  not  a  greater  depth. 

Governing  the  deposit  of  detritus. 

There  can  be  no  doubt  but  that  the  gravel,  sand,  and  much  of  the  finer  sediment  brought 
down  by  these  rivers  can  be  deposited  almost  wherever  it  is  desired  to  place  them  within  the 
territory  now  covered  by  the  sediments,  and  held  there  permanently  by  brush  work  only,  to  a 
height  varying  from  one  to  twenty  feet,  in  addition  to  the  depth  of  detritus  already  in  place. 

The  practical  limit  to  thus  disposing  of  this  sand  will  be  found  in  the  leveeing  to  prevent  the 
overflow  of  adjacent  lands. 

Recent  river  works  have  shown  in  a  wonderful  degree  what  complete  control  the  engineer 
may  have  over  the  currents  and  their  sediments,  if  he  only  study  his  subjects  closely  and  seize 
upon  local  advantages. 

We  all  know  that  a  lattice  fence,  forms  a  complete  wind-break.  Sands  blown  up  from  the 
beach  are  arrested  and  made  to  pile  up  in  great  dunes  or  ridges  parallel  to  the  water  front  by 
the  construction  of  light  wicker  work  or  brush  fences. 


16 

of  this  kind  are  numerous  in  older  countries,  and  the  experiment  was  successfully 
carried  on  f<>r  several  seasons  under  my  direction  at  the  seaward  end  of  Golden  Gate  Park  in 
San  Franei 

Similar  constructions  which  do  not  present  enough  resistance  to  the  currents  of  water  to  be 
swept  away  or  undermined  by  them  are  now  used  to  gradually  check  their  velocity  and  to  force 
them  to  drop  their  sands — like  those  blown  by  the  winds  from  the  beach — where  the  engineer 
desire-  to  have  them  rest. 

Within  the  last  two  years,  upon  the  Missouri  River,  near  Omaha,  a  greater  advance  has  been 
made  in  this  class  of  work  than  was  previously  chronicled  to  my  knowledge. 

I  here  quote  from  a  popular  account  of  these  operations,  recently  published  in  the  Scientific 
••••ferring  711  ore  extended  notice  of  the  official  report  spoken  of,  and  the  detail's"  of 
works,  until  I  submit  to  you  a  special  report  on  the  improvement  of  the  larger  streams  in  your 
district. 

Experience  on  the  Missouri  River. 

Speaking  of  the  Missouri  River,  the  journal,  after  describing  the  action  of  the  stream  at  cer- 
tain points,  says  : 

••  To  keep  the  river  within  regular  bounds  the  yielding  banks  have  to  be  protected,  the 
velocity  of  the  current  diminished  in  certain  places/and  the  channel  held  in  place  by  building 
up  or  solidifying  its  sides.  The  different  means  employed  in  this  sort  of  work  are  described  by 
Captain  llanbury  of  the  Engineer  Corps,  in  a  recent  report  upon  the  condition  of  the  Missouri 
Kiv.-r,  near  Omaha.  For  causing  deposits  to  take  place,  and  for  deflecting  the  currents  in 
localities  that  are  to  be  built  out,  floating  brush  obstructions  have  been  applied  with  marked 
success.  The  most  successful  of  these  is  the  floating  brush  dike,  7iiade  by  taking  saplings  from 
twenty  to  thirty  feet  long,  and  from  four  to  six  or  eight  inches  in  diameter,  and  nailing  or 
na  to  them  with  wire,  scraggy  brush  of  any  kind  obtainable  in  the  locality.  This  forms 
what  is  known  as  the  'weed.'  Instead  of  the  saplings  rope  may  be  used  to  hold  the  brush.  To 
one  end  of  this  'weed'  is  attached  an  anchor  of  sufficient  weight  to  hold  it  in  position  against 
the  current  j  to  the  other  a  buoy  to  hold  up  the  down  stream  end  and  prevent  it  from  going  to 
the  bottom  under  the  pressure  of  the  current  against  it.  These  'weeds'  are  placed  from  ten  to 
twenty  feet  apart,  thus  forming  the  floating  dike.  Their  action  is  to  check  the  current 
gradually,  without  producing  that  scouring  effect  to  which  the  solid  dike  gives  rise.  This  done, 
a  portion  of  the  material  which  is  rolling  along  the  bottom  or  being  carried  down  in  suspension 
is  deposited,  and  causes  a  rise  in  the  bed  of  the  river,  which  changes  its  channel  to  the  direction 
desired.  The  rapidity  with  which  these  deposits  take  place  is  truly  wonderful.  One  season  is 
often  sufficient  to  raise  the  river  bed  up  to  the  limits  of  ordinary  high  water. 

"Another  form  of  obstruction  that  has  been  tried  with  success  is  the  willow  curtain.  This, 
os  iis  name  indicates,  is  7nade  of  willows  about  an  inch  in  diameter  or  larger,  fastened  parallel 
with  each  other,  and  from  six  to  eight  inches  apart,  by  means  of  wire.  The  curtains  can  be 
made  of  any  desired  width  and  length.  They  are  anchored  in  position  by  weights  attached  at 
intervals  along  the  lower  edge,  aiid  held  in  an  upright  or  inclined  position  in  the  water  by 
floats  made,  fast  to  the  upper  edge.  Their  action  is  similar  to  that  of  the  '  weeds.' 

"Another  form  that  has  been  experimented  with,  and  which  bids  fair  to  give  good  results,  is  a 
screen  made  totally  of  wire,  something  after  the  fashion  of  a  seine.  It  is  anchored  and  buoyed 
like  the  willow  curtain.  The  rootlets  and  small  vegetable  fibers  that  float  in  large  quantities  in 
the  water  accumulate  upon  the  wires,  and  form  obstructions  sufficient  to  check  the  velocity  of 
the  current." 

Application  of  the  above  experience. 

Here  we  find  remarkably  favorable  results  produced  in  a  deep  and  rapid  river,  by  methods 
the  most  economical  and  safe  in  their  application.  It  only  requires  an  intelligent  study  of  our 
circumstances  here  to  apply  S07iie  one  of  these  contrivances  successfully  in  each  case. 

For  instance.  I  do  not  doubt  that  the  Yuba  River,  now  coursing  down  the  line  of  the  north 
levee,  for  about  three  miles  of  its  length,  transporting  a  great  volume  of  sediment  past  it  daily, 
can  be  made  to  deposit  this  load  where  it  now  threatens  erosion,  by  the  use  of  some  such  means  as 
the  brush  curtain  applied  on  the  Missouri  River.  Thus,  by  checking  the  current  at  short  inter- 
vals by  these  screens,  we  would  build  up  a  levee  strong  enough  to  resist  all  attacks  of  the 
floods — for  there  is  no  reason  why  it  should  not  be  a  thousand  feet  through  on  the  base,  all 
deposited  by  the  water  itself  up  to  the  height  of  the  flood  line. 

These  screens  are  really  open  work  brush  dams,  and  act  as  has  been  described  before  of  such 
works. 

There  are  circumstances,  then,  under  which  pervious  brush  dams  may  be  used  to  advantage 
on  the  Yuba  and  Bear  Rivers,  but  to  store  the  great  mass  of  sands  that  are  to  come  down  these 
rivers,  eve»  during  the  first  few  years  of  this  work,  more  substantial  structures  will  be  required 
of  brush  and  grave),  and  in  the  future  the  great  mass  of  detritus  must  be  held  by  rock  dams 
between  the  foothills  as  before  described ;  unless,  indeed,  it  is  proposed  to  let  these  sands  spr.-ad 
over  large  areas  of  land  as  yet  uninjured. 

And  bore  I  remark  that  the  application  of  this  idea  of  causing  the  waters  to  deposit  their 
burden  of  detritus  by  opposing  at  short  intervals  permeable  obstructions  to  their  flow,  is  almost 
illimitable. 

By  the  use  of  heavy  brush  curtains  trailing  in  the  waters,  a7id  swung  from  shore  to  shore  in 


17 

the  wider  parts  of  the  river  canons  by  means  of  cables,  it  would  be  possible  to  arrest  the  great 
mass  of  sands  between  a  series  of  low  rock  brush  rapids,  and  thus  fill  up  the  whole  canon  for 
a  number  of  miles  in  length  at  once,  without  the  use  of  any  heavy  dams  at  all. 

The  cost  of  the  work  would  probably  be  excessive,  however,  and  the  plan  is  only  mentioned 
to  show  to  what  extent  the  possibilities  in  this  matter  reach.  It  is  evident  that  sediment-bear- 
ing waters  may  be  made  to  deposit  their  load  under  any  ordinary  circumstances;  but  it  is  also 
clear  that  if  the  waters  are  to  continue  to  run  over  the  deposit,  some  more  stable  obstructions 
must  be  introduced  to  prevent  subsequent  erosion.  Hence  the  introduction  of  the  rock  and 
brush  riffles  spoken  of  above. 

Our  work  not  an  experiment  in  the  popular  sense. 

It  is  well  in  this  connection,  also,  to  allude  to  one  more  point.  It  has  been  said  that  this  work 
is  altogether  experimental.  This  assertion  is  not  correct. 

Nothing  is  more  certain  than  that  the  flow  of  these  sands  can  be  arrested  before  they  reach 
the  main  ri.vers;  the  engineering  principles  upon  which  we  are  to  work  are  well  understood, 
and  their  operation  proven. 

But,  under  the  particular  circumstances  which  we  have,  there  is  a  question  as  to  how  the 
object  can  be  most  cheaply  accomplished. 

To  this  extent  the  work  is  experimental,  and  if  carried  forward  intelligently  it  cannot  but 
result  in  showing,  after  the  first  year  or  two  of  trial,  wherein  economies  may  be  practiced  and 
the  object  attained  at  less  cost,  as  all  river  works  have  before  it. 

SPECIFICATIONS    FOR    BRUSH    WORKS. 

On  this  day  I  hand  you  specifications  for  brush  dams  on  the  Yuba  and  Bear  Rivers. 

They  are  drawn  for  heavy  dams,  intended  to  become  rapidly  impermeable  as  the  muddy 
water  flows  over  them,  and  upon  the  principle  heretofore  laid  down.  In  my  opinion,  it  will  be 
necessary  to  put  such  structures,  at  least,  across  all  open  channels  where  the  force  of  the  current 
at  flood  time  is  to  be  resisted,  and  it  is  intended  to  cause  a  deposit  for  the  full  width  of  the 
stream  ;  in  other  words  to  store  the  detritus  above  the  dam. 

Where  the  line  of  a  dam  is  located  through  a  heavy  growth  of  brushwood,  or  young  timber, 
the  character  of  the  structure  may  be  changed  so  as  to  effect  a  material  saving  in  construction. 

A  belt  of  such  timber  left  standing  forms  a  dam  for  our  purposes  itself,  and  taken  as  the 
framework  of  a  permeable  dam,  this  kind  of  a  structure  might  be  put  up  through  such  a  belt 
at  a  very  moderate  cost,  in  line  with  the  heavier  dams  across  the  open  channels. 

I  do  not  attempt  to  draw  specifications  for  this  class  of  work  at  this  time.  Indeed,  so  much 
will  depend  upon  the  exact  character  of  the  growth  itself,  that  it  will  be  necessary  to  examine 
each  line  in  detail  before  any  such  attempt  can  be  made  to  advantage. 

When  the  lines  of  the  proposed  dams  can  be  gone  over  after  the  water  has  fallen  somewhat 
more,  I  will,  if  desired,  make  specifications  as  are  required. 

Difficulty  of  describing  river  works  in  detail  before  construction. 

Here  let  me  call  attention  to  the  difficulty  of  drawing  a  description  of  such  works  sufficiently 
in  detail  upon  which  to  contract. 

The  best  laid  plans  for  this  class  of  river  works  have  almost  always  to  be  changed  to  suit  the 
peculiar  circumstances  and  conditions  found  or  developed  during  the  course  of  operations. 

Frequently  it  may  cost  near  as  much  to  make  the  examinations  necessary  upon  which  to  base 
specifications  for  such  works  as  it  would  cost  to  do  the  work  itself  under  management,  where 
there  was  latitude  for  the  exercise  of  discretion  on  the  part  of  the  engineer  in  charge. 

And  I  desire  to  be  understood  now  as  saying  that  much  must  be  left  to  the  judgment  of  the 
engineer  in  charge,  who,  as  the  work  progresses,  should  fit  its  details  to  the  conditions  pre- 
sented. 

For  this  reason  it  would  be  much  better  if  this  work  could  be  done  by  day  labor,  and  not 
under  contract;  though  it  is  possible  that  the  objections  to  this  arrangement  from  other  causes 
would  more  than  counterbalance  the  advantages  presented  upon  the  score  just  spoken  of.  And 
yet  I  cannot  see  how  the  thousand  and  one  little  jobs  of  work,  which  I  may  with  truth  call 
stitches  in  time,  that  will  have  to  be  carried  forward  by  your  Engineer,  can  be  done  by  contract. 
It  will  cost  as  much  to  advertise  some  of  them  as  it  will  to  do  them. 

Very  respectfully,  your  obedient  servant 

WM.  HAM.  HALL, 

State  Engineer. 

From  the  foregoing  reports  it  will  be  observed  that  in  consonance 
with  the  law  ^  under  which  we  are  acting,  the  sole  object  of  our 
endeavors  is  directed  to  promoting  drainage,  and  while  some  of  the 
operations  may,  to  a  secondary  extent,  produce  results  apparently  at 
variance  with  this  theory,  yet,  in  every  instance,  the  primary  object 
3" 


18 

has  been,  and  is,  to  expend  the  funds  intrusted  to  our  management, 
in  such  manner  only  as  will  further  the  end  in  view,  viz.:  to  so 
improve  the  regimen  of  the  main  artery,  the  Sacramento  River,  that 
it  may  safely,  and  with  certainty,  conduct  the  waters  o£  its  tributa- 
ries to  the  great  outlet  which  nature  has  provided.  As  a  sequence 
of  this  result,  the  navigation  of  the  Sacramento  will  doubtless  be 
improved,  the  lands  adjacent  to  the  stream  will  gain  protection,  the 
debris  from  the  mines  will  be  arrested,  and  many  minor  advantages 
gained,  but  they  are  all  secondary,  and  dependent  upon  the  one  pri- 
mary object. 

It  will  also  be  observed  that  two  general  classes  of  works  are  rec- 
ommended, the  first  being  preventive,  and  having  for  its  object  the 
restraining  and  impounding  the  sands  of  the  tributaries,  and  thus 
preventing  their  entrance  into  the  navigable  waters  of  the  main 
streams  ;  the  second,  remedial,  and  intended  to  improve  the  channels 
of  the  streams  as  flood-carrying  and  navigable  channels.  In  pur- 
suance of  the  first  of  these  objects,  and  for  the  purpose  of  arresting 
the  flow  of  detritus  from  the  mines,  we  have  caused  to  be  constructed 
permeable  brush  dams  across  the  Yuba  and  Bear  Rivers. 

That  upon  the  Yuba  is  located,  approximately,  seven  and  one-half 
miles  above  Marysville,  is  nine  thousand  six  hundred  feet  in  length, 
and  has  an  average  height  of  seven  feet. 

That  upon  Bear  River  is  located  at  Johnson's  Old  Crossing,  about 
three  miles  above  Wheatland,  is  six  thousand  feet  in  length,  and  has 
an  average  height  of  six  (6)  feet. 

The  following  specifications  will  serve  to  illustrate  the  mode  of 
construction  of  those  dams,  it  being  premised  that  the  one  on  the 
Yuba  is  located  at  what  is  designated  as  Site  Number  Two  (2),  and 
not  at  the  point  first  proposed,  and  that  the  specifications  were  some- 
what modified,  both  before  the  work  began  and  during  its  progress. 
For  an  account  of  these  modifications,  and  the  reason  therefor,  we 
refer  to  the  report  of  the  State  Engineer,  which  will  be  submitted  to 
you. 


19 


SPECIFICATIONS 

FOR    A    BRUSH    DAM    ON  THE  YUBA    RIVER,    DRAWN    FOR    PROPOSED    LINES    FOR 
DAM    NUMBER  ONE. 


DAM     EIGHT     FEET     HIGH. 


Cross   section   of  dam,  exclusive  )    ,nn  f    _ 

of  backing . }  400  square  feet. 


EXCAVATION — 


Pit  at  heel  of  dam 64 

Pit  at  toe  of  dam 130 

194 

Solid  contents  of  the  ) 

timberand  brushin  [•  10. 37 cu. yds. (2. 19  cords) per  1  footofdam. 
the  dam,  70  per  cent.  J 

Ballast  in  dam,  30  per  cent.    4.44  cu.  yds.  per  1  ft.  of  dam. 

Gravel  backing 2.00  cu.  yds.  per  1  ft.  of  dam. 

Excavation 7.19  cu.  yds.  per  1  ft.  of  dam. 


TREES  REQUIRED  PER  ONE  FOOT  OF  DAM. 

1.35  trees,  8  inches  in  diameter,  33  feet  long. 
1.35  trees,  8  inches  in  diameter,  34  feet  long. 
1.35  trees,  8  inches  in  diameter,  35  feet  long. 
1.35  trees,  8  inches  in  diameter,  36  feet  long. 
3.60  trees,  6  inches  in  diameter,  17  feet  long. 
3.60  trees,  6  inches  in  diameter,  16  feet  long. 
3.60  trees,  6  inches  in  diameter,  15  feet  long.  ' 
3.60  trees,  6  inches  in  diameter,  14  feet  long. 
4.32  trees,  7£  inches  in  diameter,  17  feet  long. 
1.44  trees,  7£  inches  in  diameter,  20  feet  long. 
1.44  trees,  7£  inches  in  diameter,  23  feet  long. 
1.54  trees,  7  inches  in  diameter,  33  feet  long. 
1.54  trees,  7  inches  in  diameter,  30  feet  long. 
1.54  trees,  7  inches  in  diameter,  28  feet  long. 
1.54  trees,  7  inches  in  diameter,  26  feet  long. 
1.54  trees,  7  inches  in  diameter,  24  feet  long. 
34.70 


20 

SITE    AND    CHARACTER    OF    THE    DAM. 

1.  The  site  of  the  proposed  dam  is  on  the  Yuba  River,  9.28  miles  in  a  direct  course  above  the 
county  bridge,  across  that  stream  at  Marysville,  and  in  a  line  immediately  across  the  general 
direction  of  the  river  from  the  long  rocky  point  which  puts  out  from  the  north  highland  shore 
into  the  sand  and  gravel  covered  bottoms,  now  occupied  by  the  waters  as  a  flood  channel. 

2.  The  alignment  of  the  work --designated  "site  of  the  proposed  dam  No.   1,"  as  determined 
upon  preliminarily,  is  shown  on  the  detail  map  of  Yuba  River,  to  be  seen  in  the  office  of  the 
State  Engineer,  or  the  office  of  the  Board  of  Directors  of  the  Drainage  District  in  the  State  Cap- 
itol building,  and  the  position  of  this  line  is  marked  at  each  end  on  the  ground  by  a  redwood 
stake,  6x6  inches  square,  to  which  is  attached  a  small  pole  and  flag;  the  post  being  marked 
with  the  brand  of  the -State  Engineer  Department  (S.  E.  D.,  !.)• 

3.  In  the  direct  course  the  distance  across  the  high-water  river  bed  between  these  posts  is 
about  4,800  feet.     The  sands  of  the  high-water  channel  occupy  about  4,600  feet  of  this  distance, 
and  vary  but  little  from  a  level  plane  in  their  profile  along  this  line,  except  at  several  points 
where  channels  three  to  five  feet  in  depth  are  cut  down.     At  their  low  stage  the  waters  run  in 
these  channels,  or  one  of  them,  to  a  depth  of  one  to  two  feet.     The  bottom  of  these  channels  are 
of  gravel,  and  the  intervening  plane,  composed  of  sand  and  gravel,  is  at  points  covered  by  a 
slight  growth  of  timber  and  brushwood.     The  northern  end  of  the  line  is  on  a  bold  rocky  point; 
the  southern  end  on  a  sloping  earth  bank. 

4.  It  is  proposed  to  construct  on  the  site  thus  described  a  dam  of  brushwood  and  gravel,  to  a 
height  of  eight  feet  above  the  average  elevation  of  the  ground's  surface,  and  it  is  presumed 
that  this  dam  will  range  in  height  from  four  to  twelve  above  the  foundation. 

5.  Accompanying  these  specifications  will  be  found  a  tracing  sheet  marked,  "  Plans  for  the 
proposed  brush  dams,"  exhibiting  cross-sectional  drawings,  with  dimensions  and  quantities  of 
materials  (as  estimated)  in    the  .proposed  dam  for  elevations   ranging  from  six  to  ten   feet, 
inclusive. 

6.  From  these  drawings  it  will  be  seen  that  the  structure  will  consist,  in  general  terms,  of 
close  crib-work,  composed  of  small  trees  with  the  branches  and  bushy  tops  for  the  most  part 
left  on,  the  spaces  between  the  trees  and  branches  being  closely  packed  with  gravel  and  small 
brushwood.     And  further,  that  the  upper  toe  of  the  structure  is  heeled  in  below  the  surface  of 
the  ground  with  its  top  on1  a  level  therewith,  while  the  main  part,  which  forms  the  dam  proper, 
rests  upon  the  natural  surface  adjusted  to  a  level  plane. 

LONGITUDINAL    DISPOSITION    OF   THE    DAM. 

7.  This  dam  is  to  be  constructed  so  that  its  crest,  as  represented  by  the  upper  edges  or  corners 
of  all  the  three  butts  which  end  at  the  top  surface  throughout  the  width  thereof  (up  and  down 
stream)  and  for  at  least  4,000  feet  uninterruptedly  of  its  length,  on  completion  and  final  accept- 
ance of  the  work,  shall  be  within  four  tenths  of  a  foot  of  one  level  plane.     So  that  allowances 
made  for  settlement  must  be  agreed  to  by  the  contractor  before  and  during  construction,  as  the 
exact  circumstances  of  foundation  and  character  of  material  are  ascertained :    and  the  work 
must  be  so  done,  at  the  contractor's  risk,  that  the  condition,  as  to  elevation  of  crest,  will  be 
present  on  final  completion  as  aforesaid. 

8.  On  completion  and  acceptance,  also,  the  down-stream  edge  of  the  dam's  crest  must  be  in 
such  alignment  that  it  will  nowhere  depart  more  than  one  foot  from  the  straight  line  forming 
its  ends,  and  the  over-fall  face  must  be  on  a  uniform  slope  of  about  forty-five  degrees,  as  shown 
in  the  drawings. 

9.  Each  way  from  the  level  portion  (the  position  of  which  will  be  designated  by  the  resi- 
dent engineer  on  commencement  of  the  work)  the  darn's  crest  must  rise  towards  the  ends  thereof 
on  slopes  of  from  two  in  one  hundred  to  six  in  one  hundred,  as  may  be  determined  upon  by 
the  resident  engineer,  preserving  a  level-topped  cross  section,  and  ending  at  an  elevation  of 
six  (6)  feet  above  the  plane  of  the  level  portion. 

10.  According  to  the  shape  of  the  ground  surface  and  character  of  the  material  found  along 
the  line,  the  foundation  of  this  structure  is  to  be  laid  in  level  benches  in  depths  below  the 
general  surface  of  the  adjacent  portions  of  the  stream-bed,  approximating  closely  to   those 
shown  on  the  diagram  of  cross-sections.     The  exact  grade  of  each  bench  or  division  will  be 
determined  by  the  resident   engineer  before  or  during  the  work   of  construction,  when  the 
character  of  the  material  and  shape  of  the  surface  becomes  known.     Each  two  adjacent  benches 
in  the  foundation  are  to  be  connected  by  a  slope  not  in  excess  of  one  on  ten  in  degree  of  incli- 
nation, and  no  bench  shall  be  less  than  one  hundred  feet  in  length,  exclusive  of  any  such 
slope. 

CROSS-SECTIONAL   DISPOSITION   OF   THE    DAM. 

11.  When  finally  completed  and  accepted  as  a  whole,  the  crest  (as  before  defined)  of  this  dam 
shall  nowhere  vary  more  than  four  tenths  of  a  foot  from  a  level  plane  in  any  line  across  it. 
The  trees  on  the  up-stream  face  of  the  dam  must  lie  in  a  plane  sloping  within  five  degrees  of 
the  inclination  which  corresponds  with  a  slope  of  one  on  two  (1  on  2),  and  its  down-stream  face  (as 
made  up  by  the  butts  of  the  trees  in  the  body  of  the  dam)  must  lie  in  a  plane  sloping  within 
five  degrees  of  that  corresponding  to  a  slope  of  one  on  one  (45°). 

12.  The  plane  of  the  lower  apron  (as  shown  by  the  red  line  in  the  cross-sectional  drawings) 
in  each  longitudinal  bench-division  of  the  work  must  be  within  two  tenths  of  a  foot  of  the 


21 

grade  set  for  it,  which  will  be  even  with  the  average  elevation,  as  at  first  found,  of  the  ground's 
surface  adjacent  to  its  lower  edge. 


FOUNDATION    OF    THE    DAM. 

13.  Upon  making  a  profile  su/vey  and  drawing  of  the  site  of  the  dam,  the  resident  engineer 
will  lay  out  the  work  in  divisions,  each  of  which  shall  be  at  least  one  hundred  feet  in  length, 
and  subsequently  the  foundation  is  to  be  laid  down  in  each  of 'such  divisions  as  a  whole,  or  in 
subdivisions  not  less  than  one  hundred  nor  more  than  two  hundred  feet  in  length,  as  may  be 
deemed  best  by  the  engineer. 

EXCAVATION. 

14.  For  at  least  half  of  such  division  or  subdivision,  as  the  case  may  be,  the  excavation  is  to 
be  made  complete  to  the  determined  sub-grade  before  the  laying  of  the  brush  is  commenced 
within  the  same. 

15.  The  work  of  excavation  may  be  carried  on  by  any  method 'to  suit  the  contractor's  con- 
venience.    Spare  material  must  not  be  left  in  a  continuous  ridge  below  the  apron,  but  such 
ridge,  if  made  in  the  process  of  excavation,  must  be  broken  through  at  one  hundred  feet  inter- 
vals, and  free  escape  ways  must  be  provided  for  the  water  on  a  level  with  the  top  of  the  adja- 
cent portion  of  the  apron  for  at  least  half  of  every  subdivision  of  the  work. 

16.  The  depth  and  width  of  the  excavations  for  a  dam  of  each  sized  section  probable  are 
shown  on  the  diagrams  heretofore  referred  to,  and  these  dimensions  are  to  be  closely  adhered  to 
in  each  instance,  on  the  average  throughout  each  division  of  the  work,  except  as" provided  in 
next  paragraph. 

17.  In  cases  where  the  material  found  in  excavation  is  not  such  as,  in  the  opinion  of  the 
engineer  in  charge,  it  is  desirable  to  build  on,  the  contractor  will  be  required  to  continue  exca- 
vation, if  necessary  so  to  do,  to  as  much  as  twice  the  depth  originally  designated  on  the  profile 
and  diagrams  of  cross-sections,  and  build  the  structure  thereon  at  the  contract  rates  for  the 
work ;  provided,  that  no  excavation  shall  ever  exceed  six  feet  in  depth  on  the  average  for  any 
one  hundred  feet  of  foundation. 

18.  It  being  understood  that  only  in  case  of  such  material  as  soft  slime  or  "slickens,"  and 

Silicic-sand  being  encountered  or  other  substances  which  would  render  the  foundation  unsafe  in 
le  opinion  of  the  engineer  in  charge,  are  the  excavations  to  be.  made  deeper  than  those  origi- 
nally set  out  on  the  profile  when  the  grades  are  first  established. 

19.  In  case  materials  of  such  consistency  that  the  foundation  pits  cannot  be  maintained 
after  excavation  are  encountered,  then,  in  the  discretion  of  the  engineer  in  charge,  the  excava- 
tions may  proceed  in  smaller  subdivisions  at  a  time  than  those  heretofore  designated,  which 
shall  be  immediately  filled  with  brush  and  gravel  to  such  an  extent  and  in  such  manner  as  the 
engineer  in  charge  may  direct. 

20.  In  general,  the   sub-grade  of  the  structure,  being  the  ground  surface  upon  which  the 
structure  is  to  rest,  is  to  be  disposed  as  shown  in  the  cross  sectional  drawings,  and  the  longitu- 
dinal profile  hereafter  to  be  made  as  aforesaid. 

THE   STRUCTURE. 

21.  Upon  the  ground  surface  thus  shaped  and  prepared,  the  structure  is  to  be  built  in  the 
following  manner : 

22.  The  lower  apron  laid  entirely  beneath  the  average  plane  of  the  ground's  surface,  is  to  be 
first  built  in  each  division  or  subdivision  of  the  work. 

23.  It  is  to  be  composed  of  small    trees,  varying  from  twenty-five  to  thirty  feet  in  length  in 
the  averaged  sized  structure  (and  of  greater  or  less  length,  as  shown  in  the  drawings  for  the 
larger  and   smaller  cross  sections),  and  four  to  eight   inches  in   thickness  of  butt,  laid   close 
together  lengthways  up  and  down  stream,  in  horizontal  layers,  separated  by  smaller  poles  placed 
at  right  angles  to  the  direction  of  the  trees  in  the  layers,  the  whole  to  be  consolidated  and  filled 
in  with  small  brush  loaded  and  incorporated  with  gravel  to  the  extent  of  thirty  per  cent,  in 
bulk  of  the  structure. 

24.  The  poles  of  each  set  are  to  be  spiked  solidly  down  upon  the  tree  trunks  below,  and  the 
trees  of  each  layer  are  to  be  solidly  spiked  down  to  the  poles  upon  which  they  rest.     Tree  nails 
of  hard  wood  may  be  used  in  this  fastening,  or  iron  spikes  of  sufficient  length  to  take  at  least 
two  and  a  half  inch  hold  may  be  used. 

25.  The  upper  apron,  laid  partially  below  and  partially  above  the  natural  surface  of  the 
ground,  is  to  be  next  built/  in  each  division  or  subdivision  of  the  work.      As  shown  in  the  sec- 
tional drawings,  this  apron  rests  partly  on  the  lower  apron  and  partly  on  the  ground,  up  stream 
from  it. 

26.  It  is  to  be  composed  of  the  same  class  of  materials  as    the  lower   apron,  and  laid  in  the 
following  manner:   Small  trees  or  trunks  of  trees,  varying  from  fifteen  to  twenty-five  feet  in 
length  in  the  average  sized  structure  (and  of  greater  or  less  length,  as  shown  in  the  drawings 
for  larger  and  smaller  sections),  and  six  to  nine  inches  thickness  of  butt — are  to  be  laid  close 
together  lengthways  up  and  down  stream,  in   layers  sloping  dowi.iw,ards  and  retreating  up 
stream,  the  butts  exposed  on  the  down  stream  edge  of  each  layer,  covered  or  buried  at  the  up 
stream  edge,  and  for  the  greater  portion  of  their  length.     Alternating  with  these  layers  of  trees, 
poles  of  smaller  diameter  are  to  be  laid,  crossing  the  trees  at  right  angles.     The  spaces  are  to  be 


22 

filled  in  with  small  brush  loaded  and  incorporated  with  gravel  to  the  extent  of  thirty  per  cent. 
of  the  bulk  of  the  structure. 

27.  The  poles  of  each  set  are  to  be  solidly  spiked  clown  upon  the  tree  trunks  below,  and  the 
trees  of  each  layer  are  to  be  solidly  spiked  down  to  the  poles  upon  which  they  rest.     Tree  nails 
of  hard  wood  may  be. used  in  this  fastening,  or  iron  spikes  of  sufficient  length  to  take  at  least 
a  four  inch  hold  may  be  used. 

THE    DAM    PROPER. 

28.  The  dam,  resting  partially  upon  the  up  stream  edge  of  the  upper  apron,  partially  upon 
the  ground's  surface  next  above,  and  partially  in  a  pit  at  the  upper  edge,  is  to  be  next  built  in 
each  division  or  subdivision  of  the  work. 

29.  Its  composition  and  the  arrangement  of  its  parts  is  similar  to  that  of  the  upper  apron. 
Small  trees  or  trunks  of  trees  fourteen  to  eighteen  feet  in    length  and  six  to  nine  inches  in 
diameter  of  butt,  are  to  be  laid  close  together  lengthways  up  and  down   stream,  in  layers 
sloping  downwards,  in  an  up-stream  direction,  the  butts  exposed  on  the  down-stream  edge  of 
each  layer.     Alternating  with  these  layers  of  trees,   poles  of  smaller  diameter  are  to  be  laid 
crossing  the  trees  at  right  angles.     The  spaces  in  the  layers  and  between  the  layers  are  to  be 
filled  in  with  small  brush,  loaded  and  incorporated1,  with  gravel  to  the  extent  of  thirty  per  cent, 
of  the  bulk  of  the  structure.      In  this  manner  the   dam  is  to  be  built  up  to   the  intended 
elevation  of  its  crest;  and  then  trees  of  larger  diameter  and  thirty  to  forty  feet  in  length  are  to 
be  used,  as  shown  in  the  sectional  drawings,  with  their  butts  in  rows  forming  the  top  surface  of 
the  dam,  their  trunks  sloping  downwards  up-stream,  on  an  angle  of  about  one  below  two,  and 
their  tops  buried  in  a  pit  and  incorporated  with  gravel  and  brush  as  in  other  cases  provided. 

30.  The  dimensions  of  materials  in  the  darn  are  given  for  the  average  sized  structures  (that 
eight  feet  high) :  larger  trees  are  to  be  used  where  the  dam  is  higher,  and  smaller  may  be  used 
where  it  is  lower. 

GRAVEL    BACKING. 

31.  On  the  up-stream  face  of  the  dam,  and  on  the  toe  thereof,  a  bank  of  gravel  is  to  be 
placed,  as  shown  in  the  drawings,  in  amounts  in  the  different  divisions  of  the  work  varying 
with  the  height  of  the  structure,  as  follows  : 

On  a  4  foot  dam,  1.00  cubic  yards  of  gravel  per  linear  foot. 
On  a  6  foot  dam,  1.50  cubic  yards  of  gravel  per  linear  foot. 
On  a  8  foot  dam,  2.00  cubic  yards  of  gravel  per  linear  foot. 
On  a  10  foot  dam,  2.50  cubic  yards  of  gravel  per  linear  foot. 
On  a  12  foot  dam,  3.00  cubic  yards  of  gravel  per  linear  foot. 

STONE    BACKING. 

32.  In  the  discretion  of  the  Board  of  Directors  a  rough  stone  backing  may  be  substituted  for 
the  gravel  backing;  this  point  to  be  determined  after  opening  the  bids  for  the  work. 

33.  In  case  such  stone  backing  is  adopted,  then  it  shall  be  placed  as  is  the  gravel  backing, 
or  as  directed  by  the  engineer  in  charge,  and  the  amount  of  stone  used  will  be  about  two  thirds 
of  those  designated  for  the  different  heights  of  dam  for  a  backing  of  gravel.     Special  figures  in 
the  bids  for  gravel  and  for  stone  will  be  required,  as  hereafter  provided. 

THE    ENDS_OF     THE    DAM. 

34.  At  the  northern  end  this  dam  is  to  be  set  in  a  bench  cut  in  the  rock  point  from  which  it 
there  springs,  in  such  manner  as  may  be  designated  by  the  engineer  in  charge;  provided,  that 
the  excavation  necessary  shall  not  exceed  600  cubic  yards  in  amount. 

35.  The  end  of  the  dam  itself  is  to  be  thoroughly  covered  and  protected  with  rough  stone,  as 
may  be  directed  by  the  engineer  in  charge;  provided,  that  the  amount  of  stone  necessary  shall 
not  exceed  1,200  cubic  yards.     The  character  and  size  of  stone  shall  be  same  as  that  for  backing, 
as  before  specified. 

36.  The  southern  end  of  the  dam  is  to  be  similarly  covered  in  and  protected,  and  connected 
with  the  face  of  the  hill  or  slope  against  which  it  will  rest,  and  the  same  provisions  are  to 

appJy- 

37.  And  all  concerning  this  end  finish  and  protection  of  the  dam  is  to  be  considered  with 
the  proviso  that  the  Board  of  Directors  may  adopt  whatever  method  or  plans  of  work  they  may 
consider  best  under  the  circumstances,  and  may,  for  as  much  as  1,000  feet  in  length,  at  the 
southern  end  of  the  work,  substitute  or  append  an  earthen  embankment  or  levee,  protected  on 
the  upper  face  by  a  rip-rap  covering  of  rough  stone,  in  pieces  not  less  than  one  cubic  foot  in 
length. 

END    TRAINING    WALL. 

38.  At  the  southern  end  of  the  overfall  of  the  dam,  a  training  wall,  built  as  a  groyne  to  the 
dam  and  in  a  similar  manner  to  the  dam  itself,  is  to  be  carried  out  from  the  lower  face  of  the 
dam  to  a  distance  of  one  hundred  feet  and  returned,  parallel  to  the  dam,  to  the  hard  bank 
land,  to  a  distance  not  exceeding  four  hundred  feet,  and  this  shall  form  a  finish  to  the  apron  at 
that  end,  and  beyond  it  no  apron  need  be  constructed. 

39.  The  connection  between  the  groyne  and  the  dain  is  to  be  made  as  the  engineer  in  charge 
may  direct,  as  are  all  connections  and  finish  in  detail  of  the  parts. 


23 

MISCELLANEOUS    PROVISIONS. 

40.  In  the  construction  of  this  dam,  it  will  be  necessary  to  turn  the  waters  of  the  stream 
from  their  low- water  channel  in  order  to  construct  therein;  and  this  work  is  to  be  done  by  the 
contractor  at  his  own  risk  and  expense,  without  compensation  other  than  provided  for  in  pay- 
ment for  the  main  work. 

41.  The  brush  and  trees  necessary  for  the  construction  of  this  dam  are  to  be  cut  off  the  sand- 
covered  flats  adjacent  to  its  site,  and  the  Directors  guarantee  to  the  contractor  the  right  to  cut 
and  remove  the  same  without  compensation  for  damages  or  payment  for  the  material;  provided, 
that  in  such  cutting  and  transportation,  the  contractor  constructs  all  necessary  roads  and  cause- 
ways, and  openings  in  fences,  etc.,  and  exercises  due  diligence  and  care  to  avoid  unnecessary 
damage;  and  further  provided,  that  the  Directors  will  not  be  responsible  for  any  damage  occa- 
sioned by  reason  of  the  escape  of  stock,  or  the  inroads  of  stock  upon  crops  or  pastures  which 
may  be  occasioned  by  the  openings  in  fences,  made  by  the  contractor,  or  in  any  way  by  the 
occupation  of  premises  by  him. 

42.  The  brush  cutting  shall  be  conducted  under  the  direction  of  the  engineer  in  charge,  and 
in'  no  case  shall  all  of  the  brush  be  stripped  from  the  land  below  the  site  of  the  dam;  but  belts 
thereof,  at  least  fifty  feet  in  width,  shall  be  left  at  five  hundred  feet  intervals,  and  extending 
across  the  general  direction  of  the  stream  so  far  as  it  grows. 

43.  The  rock  necessary  in  the  construction  of  this  dam  shall  be  quarried  half  on  the  north 
side  of  the  stream  from  the  down  stream  face  of  the  point  against  which  the  dam  is  to  rest,  at 
such  point  as  the  engineer  in  charge  may  direct,  and  half  on  the  southern  shore  of  the  river,  in 
the  rocky  point  just  above  the  dam  site. 

44.  The  Directors  guarantee  the  contractor  the  right  to  quarry  and  remove  this  rock  without 
compensation  for  material,  or  damages  under  the  same  provision  as  heretofore  enu'merated  in 
the  matter  of  cutting  and  removing  brushwood  for  the  dam. 

45.  The  Directors  guarantee  to  the  contractor  the  right  of  way  for  the  transportation  of  all 
material  on  such  routes  as  may  be  reasonably  practicable,  and  on  conditions  as  respects  liability 
for  damages,  similar  to  those  already  inserted  in  the  section  concerning  brush  cutting. 

46.  All  brusjh   cut  and  all  rock  quarried  in  the  prosecution  of  this  work,  and  remaining 
unused  at  its  completion  or  forfeiture  of  contract,  is  to  revert  to  the  Board  of  Directors,  and  the 
contractor  is  not  to  lay  claim,  after  the  work  is  done,  to  any  peculiar  privileges  of  right  of 
way,  or  right  to  material  of  any  kind  other  than  his  plant  of  tools  and  appliances  which  may 
be  removed  from  the  premises. 

47.  Whenever  the  word  gravel  is  used  in  these  specifications,,  it  is  to  be  taken  as  meaning  the 
best  material  of  the  kind  to  be  found  along  the  line  of  the  structure,  or  within  500  feet  thereof; 
it  shall  not  contain  more  than  30  per  cent,  of  sand,  and  must  pass  inspection  of  the  engineer  in 
charge. 

LAYING    OUT    AND    MEASUREMENT   OF    WORK. 

48.  This  work  is  to  be  staked  out  by  the  resident  engineer,  under  the  direction  of  the  State 
Engineer,  and  is  to  be  carried  forward  to  the  satisfaction  of  the  engineers  and  the  Board  of 
Directors  of  the  district. 

49.  Measurements  for  works  of  certain  dimensions  are  given  on  the  exhibits  and  schedule 
hereunto  appended,  and  made  a  part  of  these  specifications  as  hereafter  enumerated.     Payment 
is  to  be  made  on  such  measurements  for  the  standard  sizes  shown,  and  for  intermediate  sizes 
payment  will  be  made  upon  dimensions  of  cross  sections  proportioned  to  the  height  of  the  dam 
above  the  ground  line  in  each  ca*e. 

50.  All  extra  work  of  any  class,  except  excavations  to  depths  below   the  limit  heretofore 
specified  (six  feet),  is  to  be  done  at  contract  prices  upon  the  measurement  thereof. 

51.  Measurement  of  work  is  to  be  agreed  to  by  the  contractor  and  resident  engineer  upon 
each  division  thereof  before  it  is  laid  in. 

52.  Work  is  only  to  be  accepted  and  approved  and  taken  off  the  contractor's  hands  upon  the 
final  completion  of  the  entire  structure. 

53.  In  case  of  any  undue  settling  of  any  part  of  the  dam  after  the  completion  of  that  part, 
the  integrity  of  the  work  is  to  be  preserved  in  such  manner  as  the  State  Engineer  may  specify 
and  the  Board  of  Directors  may  direct,  and  consequent  differences  between  the  contractor  and 
the  Board  of  Directors  are  to  be  made  by  the  Directors  and  in  their  discretion. 

54.  The  work  is  to  be  prosecuted  from  its  two  ends  simultaneously,  and  with  all  due  dili- 
gence and  dispatch,  and  brought  forward  in  the  manner  and  order  directed  by  the  engineer  in 
charge. 


AMENDMENTS  TO  FOEEGOING  SPECIFICATIONS, 
Prepared  at  request  of  the  Board  of  Directors,  District  No.  1,  July  6,  1880. 

55.  The  foregoing  specifications  are  to  govern  the  construction  of  the  contemplated  dam, 
except,  in  case  trees  of  proper  size  cannot  be  secured  in  sufficient  number  for  the  purpose  within 
2,000  feet  of  site  of  the  work,  when,  after  close  examination,  the  Board  of  Directors  may  curtail 
the  dimension  of  the  dam  in  cross  section. 


24 

• 

56.  And  again,  should  the  supply  of  small  trees — as  called  fot-  in  the  specifications — to  be 
found  within  2,000  feet  of  the  work  prove  to  be  insufficient  to  complete  the  structure  to  the 
dimensions  finally  determined  upon  by  the  Board  of  Directors,  the  contractor  may  substitute 
bundles  or  fascines  of  smaller  trees  or  brush  saplings,  made  and  laid  under  the  direction  of  the 
engineer  in  charge. 

57.  The  fascines  are  to  be  made  where  the  brush  is  cut,  in  lengths  proper  to  substitute  for 
the  small  trees  called  for  in  the  specifications;  are  to  be  made  in  presses,  as  shown  in  a  cut 
accompanying  these  specifications,  or  in  some  way  insuring  equally  good  manufacture,-  and 
are  to  be  firmly  bound,  at  four-foot  intervals,  with  No.  16  (Birmingham  gauge)  iron  wire. 

FASCINE    CONSTRUCTION. 


58.  These  fascines  are  to  be  substituted  for  the  trees  where  designated  by  the  engineer  in 
charge,  are  to  be  pegged  down  and  together  firmly,  and  treated  in  all  respects  as  are  the  trees 
in  the  structure;  prodded,  that  the  top  course  at" the  upper  edge,  and  that  at  the  lower  edge 
of  the  dam's  crest,  and  the  course  at  the  foot  of  the  overfall  shall  be  composed  entirely  of  trees ^>f 
the  dimensions  and  otherwise  as  at  first  specified. 

BIDS    FOR   THE    WORK. 

59.  The  work  to  be  executed  in  completing  this  structure  is  classified  as  follows:  1 — Exca- 
vation for  foundation;  2— Brush  and  timber  ballasted;  3— Gravel  backing;  4— Stone  backing: 
5 — Stone  weighting  and  protection  of  ends  of  the  dam;  6 — Earthwork  embankment  or  levee  at 
south  end  of  the  dam. 

60.  Excavation. — Includes  removal  and  disposal  of  all  material  to  be  handled  iu  preparing  a 
formation  for  the  dam  and  the  auxiliary  works. 

61.  Brush  and  timber,  ballasted — Includes  the  cutting  and  transportation  of  brush  and  tim- 
ber, the  excavation  and  transportation  of  gravel  for  ballast,  the  laying  of  these  materials,  and 
completion  of  the  structure  composed  of  them  as  before  specified. 

62.  Gravel  backing — Includes  the  excavation,  transportation,  and  depositing  of  this  material 
as  heretofore  outlined. 

63.  Stone  backing — Includes  the  stripping  and  opening  of  quarries,  excavation"  transportation, 
and  laying  of  stone  according  to  specifications  and  directions. 

64.  Stone  weighting  and  protection — Includes  work  as  provided  above  under  headxof  "Stone 
backing." 

65.  Earthwork  embankments — Includes  the  construction  of  an  earthwork  levee  not  over  1,200 
feet  long  at  south  end  of  dam,  containing  about  five  cubic  yards  of  material  per  linear  foot. 
The  work  to  be  done  with  scrapers  and  as  directed  by  the  engineer  in  charge. 

Bids  are  desired  for  this  work  as  follows  : 

66.  For  the  excavation  :  Per  cubic  yard,  measured  in  the  pit. 

67.  For  the  brush  and  timber  ballasted  :  Per  cubic  yard,  measured  in  the  work  (predetermined 
allowances  for  settlement  not  counted  in.) 


25          ..     '•   J    .;  ;'        :-:>/;'•.•  ;...", 
• 

68.  For  gravel  backing  :  Per  cubic  yard,  measured  in  place  on  completion. 

69.  For  stone  backing :  Per  cubic  yard,  measured  in  place  on  completion. 

70.  Stone  weighting  and  protection :  Per  cubic  yard,  measured  in  place  on  completion. 

71.  Earthwork  embankment :  Per  cubic  yard,  measured  on  completion  (predetermined  allow- 
ances for  settlement  not  counted.) 

SPECIFICATIONS    FOB   THE    DAM    AT   SITE    NO.    2,   ON    THE   YUBA    RIVER. 

These  specifications,  so  far  as  the  composition  and  construction  of  the  dam  are  concerned,  are 
substantially  the  same  as  those  for  the  dam  at  site  No.  1. 

The  points  of  difference  are  shown  in  the  following  synopsis  of  specifications  for  the  dam  at 
site  No.  2. 

1.  The  proposed  dam  site  No.  2  is  two  (2)  miles  below  site  No.  1. 

2.  The  line  is  marked  on  the  ground  similarly  to  line  No.  1,  and  on  the  map  is  shown  as 
"Line  of  proposed  dam  No.  2." 

3.  In  the  direct  course  the  distance  across  the  high-water  channels  and  intervening  flats  of 
the  river  is  about  9,600  feet,  and  consequently  the  dam  proper  will  be  about  this  length. 

Paragraphs  4  to  31,  inclusive,  are  the  same  as  in  specifications  for  dam  at  site  No.  1. 

Paragraphs  32  to  36,  inclusive,  are  omitted. 

37.  End  finish  :  The  ends  of  the  dam  are  to  be  raised  gradually,  so  that  water  will  not  run 
over  its  crest  within  at  least  100  feet  of  the  ends  proper,  and  these  are  to  be  joined  with  the 
natural  bank,  or  with  earthwork  embankments. 

Paragraphs  38  and  39  are  the  same,  with  the  exception  that  there  must  be  a  training  wall  at 
both  ends  of  the  dam,  at  site  No.  2. 

Paragraphs  40  to  58,  inclusive,  are  the  same. 

Paragraph  59,  leave  out  "stone  backing,"  and  "stone  weighting,"  and  change  numbering 
to  suit. 

Paragraphs  60  to  62,  inclusive,  the  same. 

Paragraphs  63  and  64  to  be  omitted. 

Paragraphs  65  to  68,  inclusive,  the  same. 

Paragraphs  69  and  70,  inclusive,  to  be  omitted. 

Paragraph  71,  the  same. 

SPECIFICATIONS    FOB   A    DAM    OF    BRUSHWOOD   AND   GRAVEL   ON    BEAR   BIVER. 

These  specifications  are  in  all  respects  similar  to  those  for  the  dam  at  proposed  site  at  No.  2,  on 
Yuba  River,  with  the  exception  that  the  site  is  described  as  being  on  a  line  directly  across  the 
river  from  a  point'  200  feet,  more  or  less,  above  the  head  of  the  levee  on  the  north  side  of  what 
was  formerly  known  as  Johnson's  Crossing,  and  the  probable  length  of  the  dam  is  about 
6,000  feet. 

The  contracts  for  the  erection  of  the  dams  were  awarded  on  August 
10th,  the  one  on  the  Yuba  River  to  Messrs.  Rideout  &  Binney,  of 
Marysville,  and  that  upon  Bear  River  to  Messrs.  Doane  &  McBean, 
of  San  Francisco. 

The  cost  of  the  works  was  somewhat  enhanced  by  the  fact  that  the 
contractors  were,  by  the  terms  of  tlieir  contracts,  required  to  com- 
plete the  structures  within  sixty  days,  the  fear  of  approaching  storms 
precluding  greater  delay.  A  variety  of  causes  combined  to  prevent 
the  completion  of  either  structure  within  contract  time,  but  fortu- 
nately the  work  was  finished  before  storms  intervened. 

It  is  too  soon,  however,  to  speak  in  the  light  of  mature  experience 
of  the  effects  to  be  produced  by  these  dams.  State  Engineer  Hall, 
who  has  made  their  construction  and  availability  a  subject  of  patient 
and  persistent  study,  is  sanguine  as  to  the  results  to  be  experienced, 
and  his  theories  have  the  approval  of  such  eminent  engineers  as 
Colonel  G.  H.  Mendell,  United  States  Engineer,  and  Captain  James 
B.  Eads,  both  gentlemen  of  world- wide  celebrity  in  their  profession, 
and  who  have,  in  their  capacity  as  Consulting  Engineers,  given  this 
work  special  attention. 

Thus  far  the  dams  promise  all  that  can  be  hoped  for.  They  check 
the  flow  of  water  and  rid  it  of  the  heavier  portion  of  its  sand,  which 
has  already  accumulated  to  a  considerable  depth  just  above  the 

4r 


structures,  and  the  water  thus  relieved  of  its  surcharged  material,  is 
permitted  to  flow  on  with  its  scouring  capacity  greatly  increased. 

LEVEE   WORK. 

The  work  of  constructing  levees  to  confine  the  waters  of  the 
Feather,  Yuba,  Bear,  and  Sacramento  Rivers  within  their  respective 
channels,  with  a  view  to  increase  the  scouring  capacity  of  those 
streams  during  flood  periods,  has  been  steadily  pushed  forward  on 
as  large  a  scale  as  the  funds  at  command  would  warrant. 

The  following  table  will  show  the  amount  and  the  purposes  for 
which  money  has  been  expended  : 

State  Engineer  Department— Payroll $12,262  00 

State  Engineer  Department — Expenses 5,158  87 

District  Engineer  Department — Payroll 7,841  41 

District  Engineer  Department — Expenses 4,086  66 

Assessors  and  Auditors  of  counties,  in  District 8,965  99 

Advertising 1,025  50 

Legal  expenses,  brush,  &e 863  50 

Salaries  of  Directors  and  Secretary 2,286  64 

Office  expenses 50  00 

Printing,  specifications,  stationery,  etc 326  65 

Paid  for  work  (per  contract) .  320,321  18 

Total .-  $363,188  40 

We  have  commenced  suits  for  condemnation  of  land  to  be  used 
for  storage  of  debris  above  the  dams,  and  material  of  which  said 
dams  are  constructed,  as  provided  for  in  section  eleven  of  the  Act 
to  promote  drainage,  and  said  suits  are  now  in  process  of  litigation. 

CONCLUSION. 

Difficult  as  has  been  the  labor  entered  upon  by  the  Directors,  they 
feel  warranted  by  experience  in  declaring  that  during  the  progress 
of  their  operations  they  have  seen  much  to  encourage  the  hope  of 
ultimate  success.  Obstacles  that  seemed  insurmountable,  have  either 
disappeared  or  proven  less  formidable  than  was  supposed.  Many 
who,  at  the  outset,  doubted  the  feasibility  of  controlling  the  large 
volume  of  mining  debris  constantly  being  sent  down  from  the  moun- 
tain gulches,  of  restoring  the  regimen  of  the  rivers,  and  teaching 
those  rivers  to  excavate  their  own  channels,  better  informed,  are 
yielding  to  the  belief  that,  by  an  intelligent  and  systematic  treatment 
of  the  whole  problem,  our  navigable  waters  may  be  saved  to  com- 
merce, the  industries  of  the  farmer  and  miner  brought  into  such 
relations  that  each  may  prosper  without  material  injury  to  the 
other,  and  the  general  welfare  be  promoted  at  an  expense  commen- 
surate with  the  object  to  be  obtained. 

w!  F.'KNOX, 

NILES  SEARLS,^ 
.Board  of  Directors  of  Drainage  District  No.  1. 

Attest :     CHARLES  M.  COGLAN,  Secretary. 


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